SPACE TECHNOLOGY, ASTRO PHYSICS AND PARTICLE PHYSICS

SPACE TECHNOLOGY, ASTRO PHYSICS AND PARTICLE PHYSICS

INTRODUCTION: SPACE TECHNOLOGY

“Two possibilities exist: either we are alone in the universe or we are not. Both are equally terrifying.”
— Arthur C. Clark

Space

• Space, also known as Outer Space, is an almost perfect vacuum, nearly void of matter and with extremely low pressure. NASA defines Space as the “Final Frontier”. Since there is a near absence of matter and hence no scattering of sunlight takes place to produce a blue sky, space appears as a black blanket dotted with stars.
• Space technically begins at Karman Line, an imaginary boundary at 100 kilometers above the mean sea level.
• Outer space has been considered a part of global commons since the 1960s. With the growing dependence on outer space assets for socioeconomic, developmental, and military purposes, there is an increase in activities and the presence of players in outer space.
• The United Nations Office for Outer Space Affairs (UNOOSA) works to promote international cooperation in the peaceful use and exploration of space.

Outer Space Treaty: (Effective from October 1967)

• The Outer Space Treaty, formally the “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space,” is a treaty that lays the foundation of international space law. India is a party to the Outer Space Treaty. There are a total of 113 parties (as of 2023) to the treaty.

 

Key Features of the Outer Space Treaty:

• Outer space is not subject to national appropriation by claims of sovereignty, by means of use or occupation, or by any other means.
• Prohibition on placing weapons of mass destruction in space or on any celestial body.
• Limited use of celestial bodies to peaceful purposes.
• Prohibits the use of celestial bodies for testing weapons of any kind, including the establishment of military bases.
• Forbids any country from claiming a resource from any celestial body as its own and treats them as the common heritage of mankind.
• Makes countries liable for any damages caused by their space objects.

 

What are the limitations of this treaty?

• It does not cover private players.
• The treaty does not have any provisions that safeguard the countries’ assets in space.
• No provisions to counter space terrorism.

Recent Update: Outer Space Treaty In the context of emerging challenges like space debris removal, space traffic management, the arms race in outer space, coordination for space situational awareness, and regulation of private sector participation, the United Nations in May 2023, in its policy brief titled “For All Humanity the Future of Outer Space Governance,” has advocated for a “New Outer Space Treaty” containing both legally binding and legally non-binding provisions. Even prior to this, in 2021, the United Nations General Assembly adopted the “Space2030” Agenda, upholding space as a driver of sustainable development.

 

Space Technology:

• Space Technology or Space Tech refers to the application of engineering principles to the design, development, manufacture, and operation of devices and systems for space travel and exploration. It includes everything from satellites and other instruments to the human aspects of space travel, such as Astronautics, etc.

 

Application of Space Technology:

• Space exploration (the universe’s origin, the formation of stars and planets, etc.) with the use of satellites, spacecraft, telescopes, etc.
• Earth Observation, Remote Sensing, Communication, Internet, Weather Forecasting, Traffic Monitoring, Global Positioning System (GPS), Global Information System (GIS), and so on.

 

SATELLITES AND THEIR ORBITS

 

Satellite:

• A satellite is a moon, planet, or machine that orbits a planet or star.
• Usually, the word “satellite” refers to a machine that is launched into space and moves around Earth or another body in space.
• Satellites do carry their own fuel supply, but it is not needed to maintain velocity in orbit. It is reserved for changing orbit or avoiding collisions with debris.

 

Different Types of Orbits and Satellites

Classification	Categories
On the basis of origin	– Natural – Man-made
On the basis of orbits	– Geostationary orbit – Geosynchronous orbit – Low earth orbit – Middle earth orbit – High earth orbit – Polar orbit – Sun-synchronous orbit
On the basis of size	– Large satellites (>1000 kg) – Medium satellite (500-1000 kg) – Small satellite (<500 kg) – Mini satellite (100-180 kg) – Micro (10-100 kg) – Nano (1-10 kg) – Pico (<1 kg) – Femto (<0.01 kg)

 

Orbit:

• An orbit is the curved trajectory that an object in space (such as a star, planet, moon, asteroid, or spacecraft) takes around another object due to gravity.

Knowledge Base: Escape Velocity and Orbital Velocity Escape velocity: Escape velocity is the minimum speed needed for an object to break free from the gravitational attraction of a celestial body without further propulsion. The escape velocity from Earth is approximately 11.2 kilometers per second. Orbital velocity: Orbital velocity is the speed at which an object needs to travel to maintain a stable orbit around a celestial body. It depends on the mass of the celestial body and the distance from its center to the object in orbit. For satellites orbiting around the Earth, it is around 7.8 kilometers per second.

 

Satellite Orbits

We can classify the orbits on the following basis:

1. Centric classifications:
   • Galactocentric orbit — An orbit around the center of the Galaxy.
   • Sun centric / Heliocentric orbit — An orbit around the Sun.
   • Geocentric orbit — An orbit around the Earth.
   • Other planet/Lunar centric orbit — An orbit around Mars or the Moon, respectively.
   • Lagrange point centric orbit — Halo orbit.

1. Geocentric orbit’s classification:

1. Based on Inclination:

• Inclination is the angle of the orbit in relation to Earth’s equator.
• Orbital inclination is the angle between the plane of an orbit and the equator.
• Equatorial orbit: An orbit whose inclination with respect to the equatorial plane is zero.
• Polar orbits: These orbits have an inclination of about near 90 degrees to the equator.
• Inclined Orbit: A satellite is said to occupy an inclined orbit around Earth if the orbit exhibits an angle other than 0° and 90° to the equatorial plane.

1. On the basis of Shape of Orbit:

• Elliptical orbit: In this type of orbit, satellites revolve around the Earth in an oval-shaped path called an ellipse, with Earth’s center at one of the two foci of the ellipse. Hence, all points on the satellite’s orbit will not be equidistant from Earth. The points that are nearest and farthest to Earth are called Perigee and Apogee, respectively.
• Circular orbit: Satellite’s motion around Earth is in a circular trajectory with Earth at its center. All points of the satellite orbit at about the same altitude from Earth.

1. On the basis of Altitude from the Earth’s surface

• On the basis of altitude from Earth, there are essentially three types of Earth orbits: High Earth / Geosynchronous orbit, Medium Earth orbit, and Low Earth orbit.
• Many weather satellites and some communications satellites tend to have a High Earth/Geosynchronous orbit, i.e., farthest away from the Earth’s surface.
• Satellites that orbit in a Medium (mid) Earth orbit include navigation and special satellites, designed to monitor a particular region.
• Most scientific satellites, including Earth Observing System, have a Low Earth orbit.

1. Low Earth orbit (LEO): Geocentric orbits with altitudes below 2,000 km — Generally used for Earth Observing Satellites.
2. Medium Earth orbit (MEO): Geocentric orbits ranging in altitude from 2,000 km to just below geosynchronous orbit at 35,786 km. Also known as an intermediate circular orbit. Generally, these orbits are used for Global Navigation Satellite System or regional navigation systems.
3. High Earth Orbit

• Geocentric orbits at or above the altitude of geosynchronous orbit (>=35,786 km).
• At this altitude (35,786 km), the satellite enters a sort of “sweet spot” in which its orbital period matches Earth’s rotation. This special, high Earth orbit is called a geosynchronous orbit, but the orbital plane is different from the equatorial plane.
• A satellite in a circular geosynchronous orbit directly over the equator (inclination at zero) will have a geostationary orbit that does not move at all relative to the ground.
• Generally, these orbits are used for weather and communication satellites.

Similarity/Difference between GEO and GSO

Geostationary (GEO)	Geosynchronous (GSO)
The orbit is in the equatorial plane, i.e., directly above the equator, and the inclination is zero. There is only one geostationary orbit. This satellite would appear stationary from the Earth. The orbit is circular.	The orbit is not in the equatorial plane; it is in an inclined orbit. There are many geosynchronous orbits. It looks oscillating but not stationary. Generally, this orbit is elliptical.

They finish one revolution around the Earth in exactly one day, i.e., 23 hours, 56 minutes, and 4.1 seconds.

 

Similarity/Difference between Low Earth Orbit and High Earth Orbit

Low Earth Orbit (LEO)	High Earth Orbit (HEO)
Good resolution — Earth observation. Fast signal transmission. Easy to launch. Low cost. Requires large constellation for full coverage of the Earth. Lower life span. Problem of space debris.	Broad coverage — Communication. High life span. Signal loss, delay. High cost. Tough to launch.

 

SPECIAL ORBITS

Sun-Synchronous Orbit (SSO):

• It is a special kind of polar orbit.
• Satellites in SSO, traveling over the polar regions, are synchronous with the Sun.
• This means they are synchronized to always be in the same “fixed” position relative to the Sun, a concept not applied to other polar orbit satellites.
• This means that the satellite always visits the same spot at the same local time — for example, passing over Kolkata City every day at noon exactly.
• Currently, India has a number of operational satellites in Sun-synchronous orbit — RESOURCESAT, CARTOSAT, OCEANSAT, and so on.

Transfer Orbits and Geostationary Transfer Orbit (GTO):

• Transfer orbits are a special kind of orbit used to get satellites from one orbit to another. When satellites are launched from Earth and carried to space with launch vehicles, the satellites are not always placed directly in their final orbit.
• Often, the satellites are instead placed on a transfer orbit — an orbit where, by using relatively little energy from built-in motors, the satellite or spacecraft can move from one orbit to another.
• This allows a satellite to reach a high-altitude orbit, like GEO, without the launch vehicle needing to go all the way to this altitude, which would otherwise require more effort.

Lagrange Points (Halo orbit):

• For many spacecrafts being put in orbit, being too close to Earth can be disruptive to their mission — even at more distant orbits such as GEO/HEO.
• The concept of Lagrange points came into the picture.
• These points were theoretically discovered by the Swiss mathematician Leonhard Euler and the Italian-French mathematician Joseph-Louis Lagrange in the 19th century.
• For a two-body gravitational system, the Lagrange Points are positions in space where a small object tends to stay if placed there. These points in space for a two-body system such as Sun and Earth can be used by the spacecrafts to remain at these positions with reduced fuel consumption.

• For two-body gravitational systems, there are a total of five Lagrange points, denoted as L1, L2, L3, L4, and L5. A halo orbit is a periodic three-dimensional orbit that orbits a point of gravitational equilibrium between two larger bodies (known as a Lagrange point).

• The first Lagrange point (L1) is located between the Earth and the Sun, giving satellites or telescopes at this point a constant view of the Sun.
• There are currently five operational spacecrafts at L1: WIND (NASA), Solar and Heliosphere Observatory (SOHO) (NASA + ESA), Advanced Composition Explorer (ACE) NASA, Deep Space Climate Observatory (DSCOVER) (NASA), and ADITYA L1 (ISRO).
• The second Lagrange point (L2) is positioned at approximately the same distance from the Earth as L1, but it is located on the opposite side of the Earth from the Sun and provides a constant view of deep space.
• Earth is always between the second Lagrange point and the Sun. Since the Sun and Earth are in a single line, satellites or telescopes at this location only need one heat shield to block heat and light from the Sun and Earth.
• There are currently four operational spacecrafts at L2, which are:

• • ESA Gaia probe
  • Joint Russian-German high-energy astrophysics observatory Spektr-RG
  • Joint NASA, ESA, and CSA James Webb Space Telescope (JWST)
  • The ESA Euclid mission
• The most used Lagrange points are L1 and L2. These are both four times farther away when compared with the distance between the Earth and the Moon — but that is still only approximately 1% of the distance of Earth from the Sun.

 

CLASSIFICATION OF INDIAN SATELLITES

Communication Satellites

• Uses: Supports telecommunication, television broadcasting (D2H), satellite news gathering, internet, weather forecasting, disaster warning, and Search and Rescue operation services.
  • Examples: INSAT (Indian National Satellite System), GSAT (Geostationary Satellite), etc.
• Indian Satellite (INSAT)/ Geostationary Satellite (GSAT):
  • The Indian National Satellite (INSAT) system is one of the largest domestic communication satellite systems in the Asia-Pacific region.
  • It is a combined initiative of ISRO, India Meteorological Department (IMD), All India Radio (AIR), Department of Space (DoS), Department of Telecommunications (DoT), and Doordarshan.
  • Established in 1983 with the commissioning of INSAT-1B.
  • Earlier, the satellites were named under the INSAT series, but now it is under the GSAT series.
  • Latest launched communication satellites: CMS-01, GSAT-30, GSAT-24, etc.

 

3.4.2 EARTH OBSERVATION SATELLITES

• Earth Observation: Carried out by remote sensing satellites, with applications in land and water resources observation (agriculture, forestry, minerals, fisheries), cartography, ocean and atmosphere observation, disaster management, and strategic use by the defense sector.
  • Examples: Bhaskar, Rohini, Indian Remote Sensing (IRS) Series, OCEANSAT, RESOURCESAT, CARTOSAT, RISAT (Radar Imaging), Earth Observation Satellites (EOS)-01, 03, 04.

Earth Observation Satellites (EOS) and Indian Remote Sensing (IRS) Satellites:

• First: Bhaskara-1 (just an experiment for observation).
• Starting with IRS-1A in 1988 (the first of the indigenous state-of-the-art remote sensing satellites), ISRO has launched many operational Indian remote sensing (IRS) satellites. Today, India has one of the largest constellations of remote sensing satellites in operation, which includes EOS series, IRS series, OCEANSAT series, RISAT series (radar imaging), RESOURCE series, CARTOSAT series, and so on.
• Latest launched satellites: EOS-04, Ind-BhutanSAT, EOS-06, EOS-07, etc.

Knowledge Base: Remote Sensing Remote sensing: The process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation from a distance (typically from satellite or aircraft). Types of Remote Sensing Systems (via satellites, radar, or airborne systems): Optical Remote Sensing, Infrared Remote Sensing, Microwave Remote Sensing, including hyperspectral sensors. The data from EOS/IRS satellites are used for several applications covering agriculture, water resources, urban planning, rural development, mineral prospecting, environment studies, forestry, ocean resources, and disaster management, and so on.

 

NISAR

• ‘NISAR’: It stands for NASA-ISRO-SAR – Earth Observation Satellite (Radar Imaging).
• NASA and ISRO are collaborating on developing a satellite called NISAR, which will detect movements of the planet’s surface as small as 0.4 inches over areas about half the size of a tennis court.
• NISAR will be the first radar of its kind in space to systematically map Earth, using two different radar frequencies.
• It will be launched from the Satish Dhawan Space Centre into a Low Earth Orbit (LEO) – sunsynchronous Polar Orbit (SSO).
• It will map the entire globe in a 12-day cycle.

Explainer: Synthetic Aperture Radar SAR refers to a technique for producing high-resolution images. Due to its precision, SAR can penetrate clouds and darkness, allowing data collection day and night in any weather conditions.

• NASA is providing the mission’s L-band synthetic aperture radar, the high-rate communication subsystem for science data.
• ISRO is providing the spacecraft bus, the S-band synthetic aperture radar, the launch vehicle, and associated launch services.

 

Primary Goals: Ecosystem, Deformation, and Cryosphere Science

• Tracking subtle changes in the Earth’s surface, ecosystem, and earthquake patterns.
• Spotting warning signs of imminent volcanic eruptions.
• Helping to monitor groundwater supplies.
• Tracking the rate at which ice sheets are melting.
• It will also provide data for infrastructure monitoring and management, such as monitoring oil spills, natural resource mapping, urbanization, and deforestation.

 

Scientific Spacecraft

• Uses: Research in areas like Astronomy, Astrophysics, Planetary and Earth Sciences, Atmospheric Sciences, and Theoretical Physics.
• Examples: SHUKRAYAAN, MANGALYAAN, CHANDRAYAAN (1, 2, 3), GAGANYAAN, ASTROSAT, XPOSAT, ADITYA-L1, and so on.

 

GAGANYAAN MISSION:

• The Gaganyaan project envisages demonstrating human spaceflight capability by launching a crew of 2 or 3 members into a 400 km orbit for a 3-day mission and returning them safely to Earth by landing in Indian sea waters. The Gaganyaan mission will be launched by the year 2025.

• Objective: Demonstration of indigenous capability to undertake human spaceflight to Low Earth Orbit (LEO).
  • Payloads:
    • Crew module – spacecraft carrying human beings.
    • Service module – powered by liquid propellant engines.
  • Launcher: GSLV Mk III, also called the LVM-3 (Launch Vehicle Mark-3), the three-stage heavy-lift launch vehicle, will be used to launch Gaganyaan.

 

Vyom Mitra: ISRO to send humanoid AI Vyommitra in unmanned Gaganyaan spacecraft ahead of human spaceflight (Monitoring module parameters, and simulating functions exactly like humans).

Recent Update: Human Space Flight India’s space agency, ISRO, plans to conduct the Space Docking Experiment (SpaDEx) next year (2024). Docking refers to connecting two flying objects in space, either to transfer men or material from one to the other or to join two structures to make a bigger one. In this experiment, two satellites would be sent to space on board a regular PSLV mission, and the two would be made to dock with each other. The Joint Statement by India and USA during the recent visit of the Prime Minister to the USA in June 2023 mentioned that NASA would provide Advanced Training to Indian astronauts at one of its facilities. Moreover, Indian astronauts undergoing training may also find themselves traveling to the International Space Station first, before the launch of Gaganyaan.

 

Gaganyaan Mission: Opportunities

• Inspires youth to take on challenges in science & technology.
• Technology developed for societal benefits.
• Additional human resource development.
• Provides a way for international collaboration & policies.
• Enhances the science & technology levels of the country.
• National project involving other institutes, academia, and industry.
• Improves industrial growth.

 

Challenges

• Financial Cost: ₹10,000 crores, with critics questioning its utility over other priorities like development of the poor & undernourished.
• Health Issues for astronauts, hostile environments, gravity, re-entry, and recovery.

 

VENUS MISSION –  SHUKRAYAAN:

To study the surface and atmosphere of Venus.

• The Shukrayaan-1 could launch in March 2028 as an orbiter headed towards neighboring planet Venus.
• This will be the Indian space agency’s first mission to Venus and is expected to have a mission life of 4 years.
• If it misses the 2024 deadline, the next window for launch will be in mid-2026 when Venus and Earth realign. This is important for spacecraft fuel efficiency when visiting other planets.
• The mission is a significant step towards exploring and studying Venus, expanding India’s space exploration beyond the Moon and Mars.
• Venus, the closest planet to Earth and believed to have formed under similar conditions, offers a unique opportunity to understand how planetary environments can evolve differently.
• The Venus orbiter will be launched with the help of GSLV MK-II.

 

ADITYA L-1 (India’s first space-based solar observatory):

The Indian Space Research Organisation (ISRO) has successfully placed its first solar scientific mission, ADITYA-L1, at the L1 Lagrange point (halo orbit) to study the Sun. Aditya-L1 became ISRO’s second space-based astronomy mission after AstroSat. Aditya-L1 was launched through Polar Satellite Launch Vehicle (PSLV) C-57.

Objective of Aditya L1:

• To study the upper atmosphere of the Sun (chromosphere and corona) in ultraviolet (UV) light.
• To investigate the physics behind chromospheric and coronal heating, partially ionized plasma, the phenomenon of Coronal Mass Ejections (CMEs), and solar flares with the help of onboard intelligence.
• To observe in-situ particles, magnetic fields, and the plasma environment.
• To study the factors affecting space weather, such as the origin of solar wind, its directional and energy anisotropy, and its composition and velocity.

 

Why is there a need to study the Sun?

• The Sun constantly influences the Earth with radiation, heat, and a constant flow of particle streams (solar wind) and magnetic fields. There are also sudden bursts and ejections of charged particles from the Sun into interplanetary space, known as Solar flares and Coronal Mass Ejections (CMEs).
• These directly affect space weather, space-reliant technologies like satellite communication networks, and can produce electric power blackouts in Earth’s higher latitudes. Since Aditya-L1 is located outside Earth’s atmosphere, its instruments will help in better understanding the Sun’s atmosphere and space weather dynamics near Earth.

 

Explainer: Interior of the Sun The Sun’s interior is divided into three parts: the core, the radiative zone, and the convective zone. Inside the Sun, energy is created in the core and is moved from the center to the surface through both radiation and convection, similarly to how bubbles move upward in a pot of boiling water on your stove.

 

Aditya-L1 Payloads

• Aditya-L1 has instruments for the observation of solar radiation and charged particles.
• Aditya-L1 carries seven payloads to observe the photosphere, chromosphere, and the outermost layer of the sun (corona) using electromagnetic and particle detectors.
• Using the special vantage point of L1, four payloads will directly view the Sun, and the remaining three payloads will carry out in-situ studies of particles and fields at L1.

 

Remote Sensing Payloads:

1. Visible Emission Line Coronagraph (VELC)
2. Solar Ultraviolet Imaging Telescope (SUIT)
3. Solar Low Energy X-ray Spectrometer (SoLEXS)
4. High Energy L1 Orbiting X-ray Spectrometer (HEL10S)

 

In-situ Payloads:

1. Aditya Solar Wind Particle Experiment (ASPEX)
2. Plasma Analyser Package for Aditya (PAPA)
3. Advanced Tri-axial High-Resolution Digital Magnetometer

CHANDRAYAAN-3:

• It is a follow-on mission to Chandrayaan-2 to demonstrate end-to-end capability of safe and soft landing and roving on the lunar surface. It again consists of a Lander and Rover configuration.

• The Chandrayaan-3 consists of:
  • Indigenous Lander Module (LM)
  • Propulsion Module (PM)
  • A Rover with the objective of developing and demonstrating new technology required for inter-planetary missions.
• The lander will have the capability to soft land at a specified lunar site and deploy the Rover, which will carry out in-situ chemical analysis of the lunar surface during its mobility. It is meant to help understand the thermal exchange and physical properties of the uppermost lunar soil.

• The Lander and Rover have scientific payloads to carry out experiments on the lunar surface. The main function of the Propulsion Module (PM) is to carry the Lander Module (LM) from the launch vehicle injection until the final lunar 100 km circular polar orbit and separate the LM from the PM.

Knowledge Base: Successful Moon Missions There are limited successful missions with soft landing on the Moon. So far, only three countries—USA, USSR, and China (Chang’e 4)—have achieved this feat. India would be the fourth country if Chandrayaan-3 is a success. Before India, missions from Israel and Japan had already failed.

• ISRO has retained the names of Chandrayaan-2 lander “Vikram” (after Vikram Sarabhai, the father of the Indian Space Programme) and the rover “Pragyan“.

• The landing site for the mission will remain the same as the previous mission: near the south pole of the Moon at 70 degrees latitude. The site was selected as it has several craters that remain in permanent shadows, increasing the chances of examining water ice. Chandrayaan-1 was instrumental in confirming the presence of water and hydroxyl molecules on the Moon.

 

Lander Payloads (1,2,3) | Rover Payloads (4,5) | Propulsion Module Payload (6):

1. RAMBHA-LP (Langmuir Probe): To measure the near surface plasma (ions and electrons), density, and its changes with time.
2. ChaSTE (Chandra’s Surface Thermo-physical Experiment): To carry out the measurements of thermal properties of the lunar surface near the polar region.
3. ILSA (Instrument for Lunar Seismic Activity): To measure seismicity around the landing site and delineating the structure of the lunar crust and mantle.
4. APXS (Alpha Particle X-Ray Spectrometer): To determine the elemental composition (Mg, Al, Si, K, Ca, Ti, Fe) of lunar soil and rocks around the lunar landing site.
5. LIBS (Laser Induced Breakdown Spectroscope): To derive the chemical composition and infer mineralogical composition to enhance understanding of lunar surface.
6. SHAPE (Spectro-polarimetry of Habitable Planet Earth): An experimental payload to study the spectro-polarimetric signatures of the habitable planet Earth in the near-infrared (NIR) wavelength range (1-17 μm).

• The current mission will follow a similar trajectory planned for the previous mission, with the orbit of the spacecraft being raised several times until it slingshots out of Earth’s gravity. Once the spacecraft reaches the Moon and is captured in its gravity, the orbit will be lowered to a 100×100 km circular orbit before making the descent.
• This is the most crucial phase of the mission. The descent phase of the vehicle has been described by the previous ISRO chief as “15 Minutes of Terror”.

Launch date: 14th July 2023 on a LVM 3 launch vehicle from Satish Dhawan Space Centre, Sriharikota.

 

ISRO has stated the following three objectives:

1. To demonstrate a safe and soft landing on the lunar surface.
2. To demonstrate the Pragyan rover roving on the moon.
3. To conduct in-situ scientific experiments.

• The mission will study the chemical composition of the lunar surface, local seismic activities, and plasma concentration, among other features.
• It is expected to support ISRO’s future interplanetary missions.

 

Recent Update: Chandrayaan-3 Findings and Japan SLIM Mission ·         Elements present on the moon surface: The Laser-Induced Breakdown Spectroscope instrument mounted on the Pragyan rover has “clearly confirmed” the presence of sulfur on the surface of the moon near the south pole. Other elements like aluminum (Al), calcium (Ca), iron (Fe), and chromium (Cr) have also been detected. ·         Rarefied plasma: The Rambha payload and Langmuir Probe have detected the presence of rarefied plasma on the surface of the moon. ·         Japan recently landed a spacecraft called SLIM (Smart Lander for Moon Investigation) on the surface of the Moon, becoming the 5th country to perform a soft landing on the Moon after the Soviet Union, the US, China, and India.

 

Chandrayaan-2 (2019):

• Consisted of an Orbiter, Lander (Vikram), and Rover (Pragyan), all equipped with scientific instruments to study the moon.
• Launcher: GSLV Mk-III.

 

Primary Objective:

• To demonstrate the ability to soft-land on the lunar surface on the ‘Far side’ or ‘Dark side of the Moon’ and operate a robotic rover on the surface (although the mission failed).

 

Scientific Objectives:

1. The moon provides the best linkage to Earth’s early history.
2. Evidence for water molecules discovered by Chandrayaan-1 requires further studies.
3. Perform on-site chemical analysis, study new rock types, etc.

 

Major Findings:

• Detected unambiguous presence of sodium, hydroxyl, and water molecules on the Moon with the help of the orbiter.
• Objective – To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements and prepare a three-dimensional Atlas of both near side and far side of moon.
• Major findings – Detected water in vapor form in trace amounts, confirmed the Ocean Magma Hypothesis, suggested evidence of lunar caves and confirmed presence of hematite at the lunar poles.

 

Chandrayaan-1: India’s first mission to the moon, launched with PSLV-C-11 ISRO in 2008.

• Objective – To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements. To prepare a three-dimensional atlas of both near and far side of the moon.
• Major findings – Detected water in vapour form in trace amounts. Confirmed the Ocean Magma Hypothesis i.e., the moon was once completely in molten state. Evidence of lunar caves formed by an ancient lunar lava flow. Past tectonic activity was found on the lunar surface. Chandrayaan-1 indicates the presence of hematite at the lunar poles.

Note – Recently, Cabinet gave approval for CHANDRAYAAN-4 Mission– The mission aims to develop and demonstrate technologies for landing on the Moon, collecting lunar samples, and safely returning them to Earth. It serves as a foundational step towards India’s planned manned Moon landing by 2040 and establishment of India Space Station by 2035.

Explainer: Far Side / Dark Side of the Moon: Because of the synchronous rotation of the Earth and Moon’s orbit, the lunar hemisphere always faces away from Earth. Compared to the near side, its terrain is rugged with a multitude of craters and lunar maria (sea). In astronomy parlance, these regions are permanently shadowed (very little sunlight reaches there), making them dark and frigid. There lies the possibility of finding water evidence in the form of ice crystals.

 

Mars Mission / Mangalyaan / MOM Spacecraft:

• The Mars Orbiter Mission (MOM), also called Mangalyaan, is a spacecraft orbiting Mars that was launched on November 5, 2013 by the Indian Space Research Organisation (ISRO).
• It is India’s first interplanetary mission, and ISRO has become the fourth space agency to reach Mars.

• Objectives:

• Study of Martian atmosphere and surface features.
• Morphology and the mineralogy of Mars.
• According to ISRO, MOM is a “technology demonstrator.” The mission showcases India’s high-tech capabilities to the world.
• In October 2022, ISRO confirmed that the Mars Orbiter spacecraft has lost communication with ground stations and the Mangalyaan mission has attained end-of-life.
• The mission will be ever regarded as a remarkable technological and scientific feat of India in the history of planetary exploration.

 

Indian Space Station: Bhartiya Antriksha Station (InSS):

• The Indian Space Station (InSS) is a planned space station to be constructed by India and operated by ISRO by 2035, joining the league of the US, Russia, and China as an elite space club.
• A space station is a habitable spacecraft capable of supporting human crew members and designed to remain in space.
• The space station would weigh 20 tonnes and maintain an orbit of approximately 400 kilometers above the Earth, where astronauts could stay for 15-20 days.
• The project is expected to be launched in the next 5-10 years (2030-35) after the completion of the Gaganyaan crewed spaceflight mission. The InSS would be used for conducting microgravity experiments and advancing India’s space capabilities.
• The InSS would be much smaller than the International Space Station (ISS), which is a joint project of five space agencies and weighs about 420 tonnes.
• As of now, the International Space Station (ISS) is the only fully functioning space station and the largest human-made body in low Earth orbit.

 

Navigation Satellite

Uses:

• Satellites for navigation services to meet the emerging demands of the Civil Aviation sector and to meet user requirements for positioning, navigation, and timing, based on the independent satellite navigation system.
• Examples: IRNSS (NavIC), GAGAN.

 

Indian Regional Navigation Satellite System (IRNSS) – NavIC (Navigation with Indian Constellation):

• IRNSS-NavIC: ISRO developed this independent regional navigation satellite system designed to provide position information in the Indian region and 1500 km around the Indian mainland.

• Simply put, the Indian Regional Navigation Satellite System (IRNSS) is similar to the GPS (Global Positioning System) of the USA, GLONASS of Russia, GALILEO of Europe, BEIDOU of China and Quasi-Zenith Satellite System (Japan – Regional)

• NaviC consists of a constellation of seven satellites. Three of its satellites are located in Geostationary orbit, and 4 are inclined to Geosynchronous orbit. However, the full NavIC system has 9 satellites, with 2 on the ground in standby mode.

• The main objective is to provide Reliable Position, Navigation, and Timing services over India and its neighborhood, ensuring fairly good accuracy to the user.
• IRNSS will provide two types of services:
  1. Standard Positioning Service (SPS), which is provided to all users.
  2. Restricted Service (RS), which is an encrypted service provided only to authorized users.
• Restricted service is known as Precision Positioning System in the case of GPS.

 

Applications of IRNSS:

1. Terrestrial, Aerial, and Marine Navigation.
2. Disaster Management.
3. Vehicle tracking and fleet management.
4. Integration with mobile phones, Precise Timing, Mapping, and Visual and voice navigation for drivers.

Recent Update: NavIC:

• Recently, it was recognized by the International Maritime Organization (IMO) as a part of the World Wide Radio Navigation System (WWRNS) for operation in the Indian Ocean Region in 2020. Recently, it has been certified by the 3rd Generation Partnership Project (3GPP), a global body for coordinating mobile telephony standards.

 

GPS Aided Geo Augmented Navigation (GAGAN):

• This is a Satellite-Based Augmentation System (SBAS) implemented jointly by ISRO and the Airport Authority of India (AAI).
• The main objectives of GAGAN are to provide satellite-based navigation services with accuracy and integrity required for civil aviation applications and to provide better Air Traffic Management over Indian airspace.
• India has become the fourth nation, after the US, Europe, and Japan, to have an inter-operable Satellite-Based Augmentation System (SBAS).

• It provides a very accurate and high-level of satellite signals for precision air navigation over the entire Indian airspace, with the capability of expanding to nearby regions.
• In May 2022, the AAI successfully conducted a light trial using the GAGAN satellite navigation system for the landing of an ATR72 aircraft belonging to IndiGo at the Kishangarh Airport in Rajasthan.
• Meteorological and Oceanographic Satellite Data Archival Centre (MOSDAC) and Visualization of Earth Observation Data and Archival System (VEDAS) are other geoportals of ISRO.

 

Experimental Satellites

• Prototypes for other purposes.
• ISRO has launched many small satellites, mainly for experimental purposes.
• These experiments include Remote Sensing, Atmospheric Studies, Payload Development, Orbit Controls, and Recovery Technology, etc.
  • Examples: Aryabhata and Rohini, etc.

 

Small Satellites

• Below 500 kg class satellite — a platform for stand-alone payloads for earth imaging and science missions with a quick turnaround time.
  • Examples: SARAL and Youth SAT, etc.

 

Student University/Academic Institute Satellites

• ISRO’s Student Satellite Programme is designed to encourage various universities and institutions for the development of Nano/Pico Satellites for communication, remote sensing, and astronomy.
  • Examples: STUDSAT, INSPIRE Sat, SDSAT, etc.

 

INDIAN SPACE RESEARCH PROGRAMME (ISRP)

Vikram Sarabhai is the pioneer of the Indian Space Programme, with various initiatives promoting science and technology application and development for the country’s socio-economic benefit.

Institutional Setup:

• In 1962, the Indian National Committee for Space Research (INCOSPAR) was formed under Dr. Vikram Sarabhai to formulate the Space Programme of India.
• The Indian Space Research Organisation (ISRO) was formed on August 15, 1969, and superseded INCOSPAR with an expanded role to harness space technology. The Department of Space (DoS) was set up, and ISRO was brought under DoS in 1972.
• The prime objective of ISRO/DoS is the development and application of space technology for various national needs.

 

Department of Space (DoS) – 1972:

• The Department of Space (DoS) is the nodal agency for space activities in India.
• It also involves outer space activities governed by United Nations (UN) treaties and principles, evolved under the UN Committee on Peaceful Uses of Outer Space (UNCOPUOS) in particular.

 

Indian Space Research Organisation

ISRO’s vision is to harness space technology for national development, while pursuing space science research and planetary exploration.

• ISRO functions in the following areas: broadcasting, weather forecasting, disaster management, geographic information systems, navigation, cartography (maps), telemedicine, distance education satellites, etc.
• Its headquarters are located in Bengaluru.

Objectives:

• Peaceful purposes of outer space.
• Establish operational space services in a self-sufficient manner.
• In the beginning, the Indian Space Programme involved the designing and fabricating of satellites and the development of launch vehicles to launch various satellites.

 

Recent Update: Indian Space Policy 2023 The Indian Space Policy 2023 establishes a single regulatory body, IN-SPACe. It attempts to foster innovation by encouraging private sector participation, which brings new ideas, innovation, and competition into the Indian space sector. As the private sector and startups gain more share in the space sector, it is expected to lead to economic growth and job creation. With increased innovation, space technology and services could become more accessible and affordable, benefiting various sectors like communication, navigation, and earth observation. By creating a single-window clearance system, the policy streamlines the regulatory process for space activities. This makes it easier for businesses to navigate the regulatory landscape and encourages more entities to participate in space activities.

 

ISRO: Regional Centres

1. Vikram Sarabhai Space Centre, Thiruvananthapuram
   • Lead Centre of ISRO.
   • Responsible for the Design and Development of Launch Vehicle Technology.
   • Successfully developed four generations of launch vehicles like SLV, ASLV, PSLV, GSLV, and SSLV.

1. Liquid Propulsion System Centre, Thiruvananthapuram and Bengaluru
   • Centre for Design, Development, and Realisation of liquid propulsion, including cryogenics.
   • LPSC activities and facilities are spread across two campuses: LPSC Valiamala (Thiruvananthapuram) and LPSC Bengaluru.
   • LPSC is augmented by the ISRO Propulsion Complex (IPRC) at Mahendragiri, Tamil Nadu.

1. ISRO Propulsion Complex, Mahendragiri, Tamil Nadu
   • Assembly, Integration, and Testing of propellant engines, cryogenic engines, and stages for launch vehicles.
   • Formerly known as LPSC, Mahendragiri.
   • IPRC, Mahendragiri is equipped with state-of-the-art facilities for realising cutting-edge propulsion technology products for the Indian space programme.
   • The activities at IPRC include assembly, integration, and testing of propellant engines, cryogenic engines, and stages for launch vehicles; high altitude testing of upper-stage engines; production and supply of cryogenic propellants for the Indian cryogenic rocket programme, etc.

1. Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota
   • The Spaceport of India is responsible for providing Launch Base Infrastructure for the Indian Space Programme.
   • This centre has facilities for solid propellant processing, static testing of solid motors, launch vehicle integration, launch operations, and range operations, including telemetry, tracking, command network, and mission control centre.

1. UR Rao Satellite Centre (URSC):
   • Located in Bengaluru, formerly known as the ISRO Satellite Centre (ISAC), it is the lead centre for building satellites and developing associated satellite technologies.

1. Space Applications Centre (SAC)
   • At Ahmedabad, works in the development of space-borne and air-borne instruments / payloads and their applications for national development and societal benefits.

1. National Remote Sensing Centre (NRSC):
   • Located in Hyderabad, responsible for remote sensing satellite data acquisition and processing, data dissemination, aerial remote sensing, and decision support for disaster management.
   • Note: The Indian Institute of Remote Sensing (IIRS) at Dehradun is a premier institute with the objective of capacity building in Remote Sensing and Geo-informatics and their applications. It was established in 1966.

1. The Human Space Flight Centre (HSFC – Bengaluru):
   • It is a body under the Indian Space Research Organisation (ISRO) to coordinate the Indian Human Spaceflight Programme. The agency will be responsible for the implementation of the Gaganyaan project.

 

PRIVATE SECTOR PARTICIPATION IN SPACE SECTOR

 

Need for Private Sector Participation:

Services:

• Communication, Navigation, Remote Sensing, Weather Forecasting, Surveillance & Reconnaissance, and Meteorological Services.
• Provisioning of Core Socio-economic Services in sectors like education, healthcare, insurance, and connectivity.

Space Infrastructure:

• Development of space-based and ground-based infrastructure such as Launch Vehicles, launch centres, satellites, rockets, space stations, etc.
• Research and Development, investment opportunities, and employment creation.

Technology:

• Technology incubation and demonstration through the ecosystem of space companies, start-ups, government agencies, academia, and industries. Self-reliance in critical technology.

Space Exploration:

• Exploration of outer space, planetary missions, international space station, and space tourism.

Human Resource Development & Young Aspirations:

• Development of talent pool, new academic standards, demographic resource utilization, industry-specific human resources, and space curiosity among the masses.

 

Power of Partnerships

Private Sector	Public Sector
Harnessing existing public resources and infrastructure to augment governmental efforts, e.g., using Spaceport of India. Cost-effective operations, service delivery, and expansion of geographical reach. Driving innovation and entrepreneurship. Bringing multiple stakeholders through a convergence approach.	Public bodies like ISRO/NASA could focus upon new frontiers like Human Spaceflight, space exploration, and planetary missions. Regulation and orderly development of the space sector. Driving private sector energy and innovation in meeting socio-economic objectives. Expanding knowledge of human societies.

Success Story of Private Sector

1. Vikram S – India’s first privately developed rocket launcher, developed by a 4-year-old start-up company, Skyroot Aerospace. It has the capacity to launch 80 kg into a 100 km low Earth orbit. Skyroot Aerospace has Vikram-I, Vikram-II, and Vikram-III in the pipeline. The last one will put a 560 kg satellite into 500 km LEO.
2. Two satellites by Indian start-ups: SpaceKidz India and Pixxel were tested at the UR Rao Satellite Centre of ISRO recently. This is a first for ISRO, which so far has only taken help in manufacturing and fabrication of various parts of satellites and rockets from the Indian industry.
3. Following the launch of “Shakuntala” earlier this year, emerging Indian space firms like Pixxel have launched the third hyperspectral satellite, Anand, for Earth observation uses.
4. Dhruva Space, a company specializing in creating full-stack space engineering solutions, used the PSLV C53 mission to successfully evaluate its Satellite Orbital Deployer before launching two nanosatellites for amateur communications using the P-dot satellite platform in the PSLV C54 mission.
5. Digantara, a Bengaluru, Karnataka-based aerospace company, created the first commercial space weather sensor.
6. Agnikul Cosmos developed India’s first private space vehicle launchpad in Sriharikota under the supervision of IN-SPACe. The Agnibaan (3D printed) launch vehicle is developed by the same start-up.

 

Challenges

1. Nascent Space Industry: India’s space economy is around $10 billion, which is just 2.6% of the world space economy. It also contributes only 0.5% to Indian GDP.
2. Lack of Insurance and Indemnification clarity in Space Law: The Draft Space Activities Bill has not been passed yet.
3. Lower Funding: Funding in India is in millions, while in the USA it is in billions. The USA and China spend 10 times and 6 times more, respectively, than India. Reasons include a lack of good business plans and risk-taking capabilities.
4. Lack of Dispute Settlement Mechanism: The inevitability of dispute emergence due to competing and diverse claims requires a robust framework for dispute resolution.
   • Example: Antrix-Devas Multimedia case, where the Government of India owes more than $1 billion to Devas Multimedia as per the order of the International Chamber of Commerce.
5. Human Resource Constraints: Lack of educational institutions, domain-specific experts, and brain drain are other issues.
6. Apprehensions: Concerns regarding the increased tendency for the commercialization of select space services (e.g., Space Tourism for affluent sections of society).
7. Monetization: Monetization of basic services in sectors like communication, navigation, and connectivity.

 

Measures to be taken:

• Technology Development
• Clear Legislative Framework
• Research and Development and Government Support
• Independent Tribunal to adjudicate disputes
• Boosting Investor Confidence

 

GOVERNMENT OF INDIA INITIATIVES

1. ANTRIX Corporation Ltd. 1992
   • It is a wholly-owned GOI company under the administrative control of the Department of Space.
   • Objective: Commercial exploitation and promotion of ISRO’s products, services, and technologies.
   • Commercial and Marketing arm of ISRO, engaged in providing space products and services to international customers.
   • Focuses on foreign market and its integration with ISRO.

 

2. NewSpace India Limited, 2019
   • NewSpace India Limited (NSIL), Bengaluru, was incorporated on 6 March 2019 and is a wholly owned Government of India company, under the administrative control of the Department of Space (DoS).
   • NSIL is the commercial arm of ISRO, responsible for enabling Indian industries to take up high-technology space-related activities.
   • It is also responsible for the promotion and commercial exploitation of the products and services emanating from the Indian space programme.
   • Examples: Production of Polar Satellite Launch Vehicle (PSLV) and Small Satellite Launch Vehicle (SSLV) through industry.

 

3. Indian Space Promotion and Authorization Centre, 2020
   • In June 2020, the Government of India created the Indian National Space Promotion and Authorization Center (IN-SPACe), an independent nodal agency under the Department of Space.
   • This is part of reforms aimed at boosting private sector participation in space-related activities or using India’s space resources.
   • IN-SPACe will be established as a single-window nodal agency, with its own cadre (chairperson and board), which will permit and oversee the activities of private companies/startups (NGPEs – non-government private entities).
   • It will regulate and promote the building of routine satellites, rockets, and commercial launch services through Indian industry and startups.
   • It will act as an interface between ISRO and private parties, assessing how best to utilize India’s space resources and increase space-based activities.
   • ISRO will remain the basic body that decides what missions are to be undertaken, but IN-SPACe will help fill the gaps.
   • The decision of IN-SPACe shall be final and binding on all stakeholders, including ISRO, and private players will not be required to seek separate permission from ISRO.

 

IN-SPACe objectives are:

1. Promote: Develop the Indian space ecosystem, accelerating the space economy.
2. Enable: Nurture NGPEs to accomplish their ventures in the space sector.
3. Authorize: Space operations and services in the country through a well-defined framework.
4. Supervise: The space activities of NGPEs in the country.

 

4. Indian Space Association, 2021

• The Indian Space Association (ISpA) is the Premier Industry Association of Space and Satellite Companies, which aspires to be the collective voice of the Indian space industry.
• ISpA will undertake policy advocacy and engage with all stakeholders in the Indian space domain, including the government and its agencies, to make India self-reliant and technologically advanced, enabling India to become a leading player in the global space arena. ISpA echoes the vision of Atma Nirbhar Bharat.
• It will act as an independent agency for enabling the opening up of the space sector to start-ups and the private sector.
• Its founding members include Larson & Toubro, Nelco (Tata Group), OneWeb, Bharti Airtel, MapmyIndia, Walchandnagar Industries, and Ananth Technology Limited. Other core members include Godrej, Hughes India, Azista-BST Aerospace Private Limited, BEL, Centum Electronics, and Maxar India.

 

LAUNCHERS

A launch vehicle or carrier rocket is a rocket-propelled vehicle used to carry a payload from Earth’s surface to space, usually to Earth’s orbit or beyond.

ISRO has developed four generations of launch vehicle technologies First Generation: SLV (Satellite Launch Vehicle) Second Generation: ASLV (Augmented Satellite Launch Vehicle) Third Generation: PSLV (Polar Satellite Launch Vehicle) Fourth Generation: GSLV (Geostationary Satellite Launch Vehicle) Latest Generation: SSLV (Small Satellite Launch Vehicle) Experimental: Sounding Rocket Futuristic: Reusable Launch Vehicle

 

First Generation: Satellite Launch Vehicle

• Satellite Launch Vehicle-3 was a four-stage launch vehicle, consisting of all solid propellants, capable of placing 40 kilograms class payloads in Low Earth Orbit (LEO) at a distance of 400 kilometers.
• SLV-3, a first in this generation, was successfully launched in 1980 from Sriharikota.
• It successfully placed the Rohini satellite (RS-1) in its orbit.
• This project was headed by Dr. APJ Abdul Kalam.
• Now, SLV is not in use.

 

Second Generation: Augmented Satellite Launch Vehicle (ASLV) – 1987

• The ASLV Programme was designed to augment the payload capacity to 150 kilograms in LEO.
• It was a five-stage launch vehicle technology, with all solid propellants.
• Now, ASLV is not in use.

Third Generation: Polar Satellite Launch Vehicle (PSLV) – 1994

• It is the third generation launch vehicle of India.
• It is the first Indian launch vehicle to be equipped with liquid stages.
• After its first successful launch in October 1994, PSLV emerged as a reliable and versatile workhorse launch vehicle of India with more than 50 consecutively successful missions by 2022.
• Besides, the vehicle successfully launched two spacecraft:
  • Chandrayaan-1 in 2008.
  • Mars Orbiter Spacecraft in 2013.
  • One IRNSS system of Regional Navigation.

 

1st Stage: Solid Engine (S-139 Engine) This stage is augmented by 6 solid strap-on boosters. 2nd Stage: Liquid Engine Vikas Engine (Vikram Ambalal Sarabhai) – Developed by LPSC and IPRC together. 3rd Stage: Solid Engine 4th Stage: Liquid Engine Features: Payload Capacity: 1750 Kg – Low Earth Orbit 1425 Kg – GTO

 

GSLV (Geosynchronous Satellite Launch Vehicle) – GSLV MK-I and MK-II

• Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) is the launch vehicle developed by India to launch communication and heavy satellites in GTO using a cryogenic third stage.
• Initially, Russian-supplied cryogenic engines were used (2001–2013) – GSLV Mark I.
• Later, the cryogenic stage was indigenously developed and inducted in January 2014 – GSLV Mark II.
• The indigenous cryogenic engine was designed in 2003. It took another four years to integrate it with the GSLV, but the first flight failed in 2010. The first successful flight was in 2014.

Explainer: Cryogenic Rocket Engine A cryogenic rocket engine is a rocket engine that uses cryogenic fuel and oxidizer; that is, both its fuel and oxidizer are gases which have been liquefied and are stored at very low temperatures. A cryogenic rocket stage is more efficient and provides more thrust for every kilogram of cryogenic propellants (liquid Hydrogen and liquid Oxygen).

 

Stages of GSLV Mk-II: 1st Stage: S139 – Solid Engine (Strap-ons Motors). The four liquid engine strap-ons used in GSLV Mk-II. 2nd Stage: Liquid Engine (Vikas engine) used in the second stage of GSLV Mk-II. 3rd Stage: CUS – Developed under the Cryogenic Upper Stage Project (CUSP), the CE-7.5 is India’s first cryogenic engine, developed by the Liquid Propulsion Systems Centre + IPRC (Testing). GSLV Mk-II. Payload Carrying Capacity: 2250 kg (GTO). 6000 kg (LEO).

 

GSLV MK-III (LVM-III)

• GSLV Mk-III, chosen to launch Chandrayaan-2 spacecraft and heavy GSAT satellites.
• GSLV Mk-III is configured as a three-stage vehicle:
  • Stage 1: Two solid strap-on motors (S200).
  • Stage 2: One liquid core stage (L110).
  • Stage 3: High thrust cryogenic upper stage (C25).

 

• Solid Rocket Boosters:

• S200 – GSLV Mk-III uses two S200 solid rocket boosters to provide the huge amount of thrust required for lift-off. The S200 was developed at Vikram Sarabhai Space Centre. The S200 solid motor is among the largest solid boosters in the world.

 

• Core Stage: L110 Liquid Stage.

• The L110 liquid stage is powered by two Vikas engines designed and developed by the Liquid Propulsion Systems Centre.

 

• Cryogenic Upper Stage: C25.

• The C25 is powered by the CE-20 engine, India’s largest cryogenic engine, designed and developed by the Liquid Propulsion Systems Centre + IPRC (Testing).

 

• Payload Carrying Capacity:

• 4000 kg (GTO).
• 10000 kg (LEO).

 

ISRO’s Small Satellite Launch Vehicle (SSLV)

• ISRO’s Small Satellite Launch Vehicle (SSLV) has been designed to meet “Launch on Demand” requirements.
• ISRO’s VSSC developed a small satellite launch vehicle.
• SSLV is meant to offer cost-effective launch services for satellites up to 500 kg in LEO and 300 kg to SSO.
• It is a three-stage all-solid vehicle to be launched into the Low-Earth Orbit.
• It is the smallest operational launch vehicle at 110-tonne.
• NewSpace India Limited (NSIL) will be the sole nodal agency responsible for providing end-to-end SSLV launch services for customers.

Experimental Launchers

• Rohini Sounding Rockets are one or two-stage solid propellant rockets used for probing the upper atmospheric regions and for space research. Currently, three versions are offered as operational sounding rockets.
• The launch of the first sounding rocket from Thumba, near Thiruvananthapuram, Kerala, on 21 November 1963, marked the beginning of the Indian Space Programme with the establishment of the Thumba Equatorial Rocket Launching Station (TERLS).

Future Launcher – RLV (Reusable Launch Vehicle)

• Traditional launch vehicles such as PSLV and GSLV can only be used once, which increases the cost of launch and makes manned missions not feasible.

 

ISRO developing technology to reuse first & second stages of rockets:

• RLV is such a launch vehicle, which re-enters the Earth’s atmosphere after launching the payload (satellite, spacecraft) into space and then lands at the target location while withstanding excessive heat and pressure.
• Thus, RLV can be used for multiple launches.
• RLV-TD was successfully flight tested on May 23, 2016 from SDSC SHAR Sriharikota.

Recent Update: Reusable Launch Vehicle

• ISRO successfully conducted the Reusable Launch Vehicle Autonomous Landing Mission (RLV LEX). The test was conducted at the Aeronautical Test Range (ATR), Chitradurga, Karnataka in the early hours of April 2, 2023.
• In the first in the world, a winged body was carried to an altitude of 4.5 km by a helicopter (Chinook) and released for carrying out an autonomous landing on a runway (ATR). The autonomous landing was carried out under the exact conditions of a space re-entry vehicle’s landing – high speed, unmanned, and precise landing from the same return path as if the vehicle arrived from space.
• The Indian Space Research Organisation (ISRO) successfully conducted the Pushpak Reusable Landing Vehicle (RLV) LEX-02 landing experiment at the Aeronautical Test Area in Chitradurga on March 22, 2024. The RLV LEX-02 landing experiment is the second in a series of experiments conducted by the space agency. The third and final RLV LEX-03 was successfully conducted on June 23, 2024.

Next Generation Launch Vehicles (NGLV):

• ISRO is developing a Next-Gen Launch Vehicle (NGLV) to replace its current operational systems like the Polar Satellite Launch Vehicle (PSLV).
• The Next-Gen Launch Vehicle is envisioned as a cost-efficient, three-stage-to-orbit, reusable heavy-lift vehicle with a payload capability of 10 tonnes to Geostationary Transfer Orbit (GTO).
• The NGLV is designed with a robust structure that allows for bulk manufacturing, modularity in systems and stages, and minimal turnaround time.
• It will utilize semi-cryogenic propulsion, which involves refined kerosene as fuel and liquid oxygen (LOX) as the oxidizer for the booster stages.
• The Next-Gen Launch Vehicle is expected to be used for various missions, including launching communication satellites, deep space missions, future human spaceflight, and cargo missions.

·         Knowledge Base: NGLV  and Reusable

There are some notable examples of NGLV: Arianespace Ariane 6 by the European Space Agency. China Aerospace Science and Technology Corporation (CASC) – rockets like Long March 5 and Long March 7. SpaceX Falcon 9 and Falcon Heavy. Blue Origin – New Shepard and New Glenn by Jeff Bezos. Rocket Lab – Electron. Virgin Orbit – LauncherOne.

 

NUCLEAR TECHNOLOGY IN SPACE MISSION

The UR Rao Satellite Centre (URSC) of ISRO invited proposals for the three-phase development of a 100-Watt Radioisotope Thermoelectric Generator (RTG).

Types of Nuclear Power Systems (NPS) with application in space missions:

Radioisotope power systems (RPSs): Use heat (produced by the natural radioactive decay of plutonium-238) to produce electric power for operating spacecraft systems and science instruments. There are two types of radioisotope power systems:

• Radioisotope Heater Units (RHU): Small devices that provide heat to keep a spacecraft’s electronic instruments and mechanical systems operational in the cold temperatures of our solar system.
• Radioisotope Thermoelectric Generator (RTG): Flight-proven systems that provide power and heat to a spacecraft. Nuclear Propulsion Systems: Nuclear power can be used for a rocket propulsion system with the help of a fission reactor.

 

Advantages of Nuclear Technology in Space

• Enables deep space and interplanetary travel as they are more fuel-efficient and lighter than chemical rockets.
• RTGs as an alternative to solar power.
• Flexible launch windows.
• Continuous operation over long-duration space missions.

 

INTERNATIONAL MISSION IN NEWS (2022-24)

Sun:

• Aditya-L1 – ISRO
• Parker Solar Probe (NASA) – Observations of the Sun’s outer corona
• Solar and Heliospheric Observatory Mission (SOHO) – (NASA & ESA)
• ESA’s Vigil Mission (future mission to Lagrange point L5)

 

Mercury:

• Messenger (NASA)
• Bepi Colombo (ESA + JAXA)

 

Venus:

• NASA:
  • DaVinci+
  • Veritas
  • Magellan
• Venus Express and ENVISION – ESA
• Akatsuki-JAXA
• Shukrayaan-ISRO

 

Mars:

• NASA – The Mars 2020 mission consists of the rover Perseverance and the robotic helicopter Ingenuity.
• NASA – Curiosity Rover
• NASA – InSight Lander
• ISRO – Mangalyaan-2 (future)
• HOPE (UAE)

• Tianwen-1 (China) – Zhurong Rover
• Mars Express and Exo Mars (ESA)

 

Asteroid:

• NASA’s Psyche Mission – (Metal-Rich Asteroid Psyche) – Future
• NASA’s Lucy Mission – to detect Jupiter’s Trojan asteroids (Dinkins).
• NASA’s OSIRIS-REX (Bennu Asteroid) – Done, part of NASA’s New Frontiers Program. The OSIRIS-REX mission has now been renamed OSIRIS-APEX (Future – for Apophis asteroid).

 

 

New Frontiers Program: New Horizons – (Deep Space, Explored Pluto) Juno – Jupiter OSIRIS-REX – Bennu Dragonfly – Titan (Moon of Saturn)

 

Jupiter:

• NASA – Juno – Part of NASA’s New Frontiers program.
• NASA – Europa Clipper – For exploring Jupiter’s moon Europa.
• ESA – Jupiter Icy Moons Explorer (JUICE) – For exploring Ganymede (the largest moon in the solar system), Callisto, and Europa – moons of Jupiter.

 

Saturn:

• NASA + ESA – Cassini-Huygens, commonly called Cassini – For Saturn and its largest moon Titan (the second largest in the solar system).
• NASA – Dragonfly is a planned spacecraft and NASA mission – for Titan.

 

Moon:

• Chandrayaan-1, 2, 3 – ISRO.
• Chandrayaan-4 (future) – LUPEX – ISRO + JAXA.
• SLIM – JAXA.
• Chang’e series – China.
• NASA – VIPER Mission – for resource and water exploration.

 

NASA:

• Artemis I: An Uncrewed Test Flight – Successfully completed. This mission was a test flight of the new Space Launch System Rocket and Orion Spacecraft without any astronauts.
• Artemis II: First manned mission – orbiting the moon with a crew and returning safely to Earth.
• Artemis III: Landing on the Moon’s South Pole – In this, astronauts, including the first woman and a man, are planned to land on the south pole of the moon and do exploration and scientific research there.

Space Stations:

• International Space Station (ISS) – NASA (USA), Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada) – End stages.
• Tiangong (Meaning “Heavenly Palace”) – China National Space Administration (CNSA) – Under development.
• Indian Space Station – Bhartiya Andariksha Station – Future.
• Mir – Operated by the Soviet Union – Retired.

• Skylab – First United States space station – retired.
• Salyut program – A series of space stations by the Soviet Union – retired.

 

Observatories Program:

• Hubble Space Telescope (NASA & ESA) (HST – 1990 – LEO).
• Compton Gamma Ray Observatory (NASA) (CGRO – 1991 – 2000).
• Chandra X-ray Observatory (NASA) (CXO – 1999).
• Spitzer Space Telescope (NASA) (SST – 2003–2020).
• James Webb Space Telescope – 2022 – (NASA), (ESA), and (CSA).
• X-ray Imaging and Spectroscopy Mission (XRISM) – 2023 – NASA + JAXA – LEO.
• ESA-Euclid – To understand dark matter and dark energy and to do 3D mapping of the universe.

 

Deep Space Mission:

• NASA, ESA-Euclid – and Pioneer-10 and 11, New Horizon (part of NASA’s New Frontier program).

 

Special Mission: Solar Parker Probe:

• The Solar Parker Probe aims to explore the mechanisms that accelerate and transport energetic particles, determine the structure and dynamics of plasma and magnetic fields at the source of the solar wind, and trace the flow of energy in the solar corona.

• For the first time in history, a spacecraft has touched the sun. By flying through the sun’s upper atmosphere, the probe samples particles and magnetic fields to unravel the mysteries of our closest star.
• It has identified the origin of magnetic switchbacks (magnetic zig-zag structure in the solar wind) near the sun’s surface.
• The study is crucial for understanding the complex, dynamic nature of the sun, predicting changes in Earth’s space environment, studying the corona and solar wind, and unraveling the unpredictable nature of solar winds’ impact on our planet’s magnetic field.

 

Importance of Study:

1. To study the far more complex sun, which is a dynamic and magnetically active star.
2. The probe results will allow scientists to foresee changes in the Earth’s space environment.
3. To study the corona, which gives rise to solar wind, a continuous flow of charged particles that permeates the solar system.
4. To determine the unpredictable nature of solar winds, which cause disturbances in our planet’s magnetic field.

JUICE: (Jupiter Icy Moons Explorer)

• It is a European Space Agency’s mission to explore Jupiter and its icy moons, namely Ganymede, Callisto, and Europa.
• Launched on 14 April 2023, from French Guiana on an Ariane 5 launcher, the mission is set to reach Jupiter in 2031.
• Only two other spacecraft have ever examined Jupiter: the Galileo probe, which orbited the gas giant between 1995 and 2003, and Juno, which has been circling the planet since 2016.
• Notably, by the time JUICE reaches Jupiter, another spacecraft, NASA’s Europa Clipper, would already be orbiting the planet – scheduled to be launched in October this year. Europa Clipper would arrive at Jupiter in 2030 and aims to study its Europa moon.

 

Mission Objectives:

• JUICE will make detailed observations of the giant gas planet and its three large ocean-bearing moons – Ganymede, Callisto, and Europa – by using remote sensing, geophysical, and in-situ instruments.
• Scientists have long believed that these three moons of Jupiter possess icy crusts, which they believe contain oceans of liquid water underneath, making them potentially habitable. JUICE will help probe these water bodies by creating detailed maps of the moons’ surfaces and enabling scientists, for the first time, to look beneath them.
• Although the mission will examine all three moons, the main focus will be on Ganymede, as it is the largest moon in the solar system – larger than Pluto and Mercury and the only one to generate its own magnetic field.
• According to ESA, life on these moons could be in the form of microbes. More advanced species might also be present, like the ones detected in deep sea trenches and at hydrothermal vents on Earth, such as various kinds of corals, worms, mussels, shrimp, and fish.
• Another primary goal of the mission is to create a comprehensive picture of Jupiter by trying to understand its origin, history, and evolution. Scientists believe this will help provide much-needed insight into how such a planetary system and its constituents are formed and evolved over time, as well as revealing how possibly habitable environments can arise in Jupiter-like systems around other stars.

 

ARTEMIS Programme:

• ARTEMIS stands for Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s interaction with the Sun. NASA, in coordination with the US Department of State, established the Artemis Accords in 2020 together with seven other founding member countries.
• Countries that signed the Artemis Accords include Australia, Canada, Italy, Japan, Luxembourg, UAE, and UK. The Artemis Accords reinforce and implement key obligations in the 1967 Outer Space Treaty.
• These are a non-binding set of principles to guide civil space exploration. The purpose of these accords is to establish a shared vision via a practical set of principles, guidelines, and best practices to enhance the use of outer space.

• Through the Artemis program, NASA will land the first women and first person of color on the Moon, make new scientific discoveries, and explore the lunar surface.
• NASA will collaborate with commercial and international partners to establish the first long-term human robotic presence on and around the Moon.
• On 16th November 2022, NASA successfully launched its unmanned Moon mission Artemis I.
• The Artemis program includes plans for a base on the lunar surface, multiple spacecraft to ferry humans and cargo, an orbiting station, and a constellation of satellites to help with navigation and communication.
• Artemis I is an uncrewed mission. The first crewed mission to the Moon’s surface is likely in 2026. The program resembles a Chinese-Russian plan for the “International Lunar Research Station.”
• It tested the NASA’s Space Launch System (SLS) rocket launcher and Orion crew capsule.
• The much-delayed launch kicked off Apollo’s successor program, Artemis, aimed at returning astronauts to the lunar surface this decade and establishing a sustainable base there as a stepping stone to future human exploration of Mars.

Recent Update: India became the 27th country to sign the Artemis Accords. Significance for India: India can work with other countries, notably the USA, on its upcoming Moon missions to share information and skills, advance scientific inquiry, technological innovation, and expand humanity’s presence in space. It will also facilitate cooperation in Indian flagship projects like the Gaganyaan Project and International Space Station.

 

Double Asteroid Redirection Test (DART) Mission:

• DART is the world’s first planetary defense mission against Near Earth Objects (NEOs), such as asteroids.
• It was launched by NASA on a SpaceX Falcon 9 rocket.
• It is NASA’s first planetary defense test mission, launched in August 2022.

• The aim of the mission is to test newly developed technology that would allow a spacecraft to crash into an asteroid and change its course.
• This mission tested new technology to be prepared in case an asteroid heads toward Earth in the future. The James Webb Space Telescope and Hubble were used to track the spacecraft.

• DART is the first-ever space mission to demonstrate asteroid deflection by kinetic impactor technology.
• The DART mission is only to test the technology. The asteroid targeted by the mission does not pose any threat to Earth.
• DART also carried a small CubeSet named – LICIACube to capture the images of the impact of the collision.

• The spacecraft was launched on a SpaceX Falcon 9 rocket.
• DART’s target is the binary asteroid system Didymos, i.e., two asteroids:
  1. Didymos: Bigger asteroid at the center of the binary asteroid system.
  2. Dimorphos: It is smaller and revolving around Didymos.

How the DART Mission Worked

• The DART spacecraft impacted Dimorphos nearly head-on.
• This reduced speed of Dimorphos due to the collision.
• The reduced speed led Dimorphos to change its orbit around Didymos.

 

Explainer: Why the binary asteroid system Didymos was chosen? The binary asteroid system Didymos involves two asteroids, Didymos and its moonlet Dimorphos. They represent a system like Earth and an asteroid revolving around it, which could be a future threat. In the future, the orbit of an asteroid around Earth can be changed similarly to how the orbit of Dimorphos, around Didymos, was changed by DART. The timing of the DART impact in September 2022 was chosen to be when the distance between Earth and Didymos was minimized to enable the highest quality telescopic observations.

 

NASA’s – Great Observatories Program:

• Four large, powerful space-based astronomical telescopes were launched between 1990 and 2003.
• The Hubble Space Telescope (HST): Observes near-ultraviolet, visible, and near-infrared.
• Compton Gamma Ray Observatory (CGRO): Observed gamma rays.
• Chandra X-ray Observatory (CXO): Primarily observes X-rays.
• Spitzer Space Telescope (SST): Observed the infrared spectrum.

1. Hubble Telescope – 1990

• The Hubble Space Telescope is a large telescope in space. NASA launched Hubble in 1990.
• It was built by the United States space agency NASA, with contributions from the European Space Agency.
• Expanding the frontiers of the visible Universe, the Hubble Space Telescope looks deep into space with cameras that can see three different kinds of light: near-ultraviolet, visible, and near-infrared. However, Hubble can only see each kind of light one at a time. Human eyes can see visible light.

2. James Webb Space Telescope – 2021

James Webb Space Telescope (JWST):

• JWST succeeded the Hubble Space Telescope.
• About JWST: JWST is placed in Sun-Earth Lagrange Point 2 (L2).
• JWST is a joint venture between the US (NASA), European (ESA), and Canadian Space Agencies (CSA).
• It is an orbiting infrared observatory that will complement and extend the discoveries of the Hubble Space Telescope, with longer wavelength coverage and greatly improved sensitivity.

Objectives of JWST are:

• Search for first galaxies or luminous objects formed after the Big Bang.
• Determine how galaxies formed and evolved.
• Observe stars formation from the first stages to formation of planetary systems.

• Measure physical and chemical properties of planetary systems, including our own Solar System, and investigate the potential for life in those systems.
• These goals can be accomplished more effectively by observation in near-infrared light rather than light in the visible part of the spectrum.
• For this reason, JWST’s instruments will not measure visible or ultraviolet light like the Hubble Telescope, but will have a much greater capacity to perform infrared astronomy.
• JWST is designed primarily for near-infrared astronomy but can also see orange and red visible light, as well as the mid-infrared region.
• The longer wavelengths of infrared light slip past dust more easily, and therefore instruments that detect infrared light—like those on Webb—are able to see the objects that emitted that light inside a dusty cloud. That’s why Webb will solve mysteries in our solar system, looking beyond to distant worlds around other stars.

Recent development related to JWST:

• Recently, JWST presented new images of Jupiter with its massive storms and colorful auroras.
• Recently, scientists at the Indian Institute of Astrophysics have developed a model to trace habitable exo-moons with the help of the James Webb Space Telescope (JWST).
• Exo-Moons: They are natural satellites that revolve around exoplanets (planets orbiting stars other than the Sun).
• Recently, James Webb Space Telescope took a picture of the ‘Einstein Ring’.

 

CHALLENGES OF SPACE EXPLORATION

Space Debris

• Space debris encompasses both natural (meteoroid) and artificial (man-made) particles. Meteoroids are in orbit around the sun, while most artificial debris is in orbit around the Earth, which is commonly referred to as orbital debris.
• Orbital debris is any man-made object in orbit about the Earth which no longer serves a useful function. This includes non-functional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris.
• Much of the debris is in low Earth orbit (within 2,000 km of Earth’s surface), though some debris can be found in geostationary orbit (35,786 km above the Equator).

• Space debris encompasses both natural (meteoroid) and artificial (man-made) particles. Meteoroids are in orbit about the sun, while most artificial debris is in orbit about the Earth, which is commonly referred to as orbital debris.
• Orbital debris is any man-made object in orbit about the Earth which no longer serves a useful function. This includes non-functional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris.
• Much of the debris is in low Earth orbit (within 2,000 km of Earth’s surface), though some debris can be found in geostationary orbit (35,786 km above the Equator).

 

Risks associated with space debris

1. Collision Threat: Space debris poses a significant threat to active satellites, space stations, and spacecraft due to high-speed collisions. Even small debris can cause considerable damage.

1. Kessler Syndrome: Proposed by NASA scientist Donald J. Kessler, this is a scenario in which the density of objects in low Earth orbit is high enough that collisions between objects could cause a cascade of further collisions, making space activities and the use of satellites potentially hazardous.

1. Damage to Space Missions: In 2009, an active satellite collided with a defunct one, creating even more debris. The International Space Station has also had to perform maneuvers to avoid potential debris collisions.

Mitigation strategies for space debris

• Active Removal: Efforts to actively remove space debris from orbit, including robotic spacecraft designed to capture and remove debris.
• De-orbiting Techniques: Satellites and spacecraft can be designed to de-orbit after their mission ends, either by burning up upon re-entry or moving to a safer “graveyard” orbit.
• Space Traffic Management: International collaboration is needed to monitor and manage the placement and movement of satellites and debris.

Explainer: The Kessler Syndrome Also called the Kessler effect, this scenario occurs when the density of objects in Low Earth Orbit (LEO) becomes high enough that collisions between objects could cause a cascade, where each collision generates space debris, increasing the likelihood of further collisions. This could lead to a situation where orbit becomes impassable in the long run.

 

Initiatives to tackle the problem of space debris

• Project NETRA (ISRO): Network for Space Objects Tracking and Analysis in Bengaluru to detect debris and other hazards to Indian satellites.
• UK’s TechDemoSat-1 (TDS-1).
• The robot NEO-01, developed by China.
• Elsa-D, by Japan.
• RemoveDebris project by the EU.

 

Space Weaponization

Space weaponization refers to the more aggressive and offensive use of space systems for military purposes. The increasing militarization of space by major powers has raised concerns about the risk of an arms race and potential conflicts that could disrupt the peaceful and beneficial use of space.

Some reasons why states may pursue space weaponization:

1. To establish military supremacy on all fronts of warfare.
2. To protect their own space assets from incoming Anti-Satellite Weapons (ASAT), designed to destroy or disable satellites in orbit, which can have global repercussions on communications, navigation, weather monitoring, and scientific research.
3. To complement warfare on other fronts, such as sea, air, and land.

Some implications of the weaponization of space:

1. Mutual suspicion and fear of war among spacefaring nations.
2. Threat to commercial and scientific missions in space due to interference, jamming, or destruction.
3. Increase in space debris and risk of collisions in orbit.
4. Monopoly of orbits by developed countries, excluding developing countries from accessing space resources.

Violation of the existing legal framework for outer space, such as the 1967 Outer Space Treaty, which declares that outer space is the common heritage of mankind and should be used for peaceful purposes only.

 

Space Tourism

The dawn of commercial human spaceflight and the emergence of suborbital flights have ushered in a new era of space tourism, offering the prospect of venturing beyond the confines of Earth for recreational purposes. While space tourism presents exciting opportunities, it also brings forth a host of challenges.

Some of the challenges of space tourism are:

1. High costs of space travel: Space tourism is still a very expensive and exclusive activity, as it requires a lot of fuel, power, and infrastructure to launch and operate spacecraft. The tickets for suborbital flights are beyond the reach of most people.
2. Life at risk: Space tourism involves exposing passengers and crew to various hazards and uncertainties in space, such as cosmic radiation, microgravity, extreme temperatures, vacuum, and high-speed impacts. There is also the possibility of accidents or malfunctions that could result in injury or death.
3. Another critical concern is the environmental impact of space tourism: Spacecraft emissions, space debris, and the potential release of pollutants can have adverse effects on the fragile space environment.

• Space tourism requires the development and regulation of new technologies and standards to ensure the safety, security, and sustainability of space activities. There is a need for more research and innovation in areas such as propulsion, reusability, life support, communication, navigation, and emergency systems. There is also a need for more clarity and consistency in the legal framework for space tourism, such as liability and insurance issues, the rights and obligations of passengers and operators, and the environmental impact of space flights.

Governance of outer space

• The existing legal framework for outer space is based on the 1967 Outer Space Treaty and other related agreements, which are outdated and inadequate to address the current and emerging challenges in space.
• The treaty declares that outer space is the common heritage of mankind and should be used for peaceful purposes only, but it does not define what constitutes peaceful use or how to resolve disputes over space activities. The treaty also does not regulate the exploitation of natural resources in space, such as asteroids or lunar minerals, which could lead to conflicts over ownership and benefit-sharing.

ASTROPHYSICS

Introduction

Astrophysics is the branch of space science that investigates the causes of the physical processes in the universe. For this, it uses data gathered by telescopes on Earth and in space. Then, it applies the laws and theories of physics to interpret the universe around us.

The field explores topics such as the birth, life, and death of stars, planets, galaxies, nebulae, and other objects in the universe. Because astrophysics is a broad subject, astrophysicists apply concepts and methods from many disciplines of physics, including classical mechanics, electromagnetism, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.

It has two sibling sciences, astronomy and cosmology, though the lines between these branches can blur. It is important to understand what each field contributes and how they differ and why.

• Astrophysics creates physical theories of small to medium-size objects and structures in the universe.
• Astronomy measures the positions, luminosity, motions and other characteristics of celestial objects.
• Cosmology covers the cosmos’ largest structures i.e. the universe as a whole.

 

Applications Of Astrophysics

There are many applications of astrophysics. Some of the most important applications include:

• Understanding the formation and evolution of stars and galaxies.
• Studying the composition of the universe: This information can be used to understand how the elements were created and to study the distribution of matter in the universe.
• Detecting and studying black holes: This information can be used to understand the properties of black holes and to study the environment around them.
• Understanding the nature of dark matter and dark energy: These are two mysterious substances that make up most of the matter in the universe.
• Astrophysics can be used to develop new technologies: For example, the development of new telescopes and detectors has been driven by astrophysics research.
• Astrophysics can be used to improve our understanding of Earth’s atmosphere and climate: By studying the atmospheres of other planets, we can learn more about the processes that affect our own atmosphere.
• Astrophysics can be used to study the effects of space radiation on humans and other living things: This information can be used to protect astronauts and other people who travel into space.

Astrophysics is a fascinating and ever-evolving field of study. It has the potential to answer some of the most fundamental questions about the universe and our place in it. As the discipline of astrophysics continues to grow and discover new phenomena, humanity can expect to see even more applications for this important field.

Knowledge Base: Indian Pioneers in Astrophysics / Astronomy Aryabhata: Aryabhata’s contributions towards astronomy and mathematics include Solar system motion (similar to the heliocentric model), accurately determined Earth’s rotation and spherical shape, explained lunar and solar eclipses, approximation of pi, and knowledge of ‘Zero’ was implicit in Aryabhata’s place value system. Varahamihira: Varahamihira’s contributions towards astronomy and mathematics include the model of the solar system, length of the solar year with great accuracy, motion of the planets and the moon, improved the accuracy of Aryabhata’s sine tables, defined the algebraic properties of zero and negative numbers, and discovered a version of Pascal’s triangle. ·         Brahmagupta: Brahmagupta contributions include the concept of gravity and the influence it has on the motion of planets, emphasizing the gravitational attraction between the Earth and other celestial objects, developed mathematical formulas and algorithms to predict the positions of the planets over time. Provided detailed explanations and accurate methods for predicting lunar and solar eclipses. In Brahmagupta calendar he incorporated lunar months and intercalary months. He also gave the symbol of Zero. 3.      Bhaskara II: His most celebrated work Siddhant Shiromani had four sections: Lilavati (arithmetic), Bijaganita (algebra), Grahaganita (mathematics of the planets), and Goladhyaya (spherical astronomy).   4.      Kapila: Rishi Kapila, the father of cosmology, gave the world the Sankhya School of Thought, which shed light on the nature and principles of the ultimate soul (Purusha) and primal matter (Prakruti). He asserted that Prakruti, with the inspiration of Purusha, is the mother of cosmic creation and all energies.

 

PHENOMENA OF ASTROPHYSICS

BIG-BANG THEORY

The most popular modern argument regarding the origin of the universe is the Big Bang Theory. It is also called the expanding universe hypothesis.

The Big Bang Theory considers the following stages in the development of the universe:

• In the beginning, all matter forming the universe existed in one place in the form of a “tiny ball” (singular atom) with an unimaginably small volume, infinite temperature, and infinite density.
• At the Big Bang, the “tiny ball” exploded violently. This led to a huge expansion. It is now generally accepted that the event of the Big Bang took place 13.77 billion years before the present. The expansion continues even to the present day. As it grew, some energy was converted into matter. There was particularly rapid expansion within fractions of a second after the bang. Thereafter, the expansion has slowed down. Within the first three minutes from the Big Bang event, the first atom began to form. Scientists have inferred that helium hydride (HeH⁺) was this first, primordial molecule.

• Within 300,000 years from the Big Bang, temperature dropped to 4,500K (Kelvin) and gave rise to atomic matter. The universe became transparent.
• The Big Bang theory does not tell us what caused the singularity to appear or what happened before it. What is the nature of the mysterious dark matter and dark energy that make up most of its mass and energy.

The Big Bang theory is supported by a wide range of evidence, including:

• Einstein field equations of general theory of relativity (1916) support that the universe is expanding.
• Early evidence of Georges Lemaitre (1927) provided a compelling solution to the equations of General Relativity for the case of an expanding universe.
• Edwin Hubble (1929) gave scientific evidence that the universe is expanding, and galaxies are moving away from each other with the passage of time because the space between them is getting expanded.
  • Edwin Hubble explained this by describing a redshift phenomenon (galactic redshift) and later linked it to the expansion of the universe.

• The cosmic microwave background radiation and the abundance of light elements in the universe are also supporting it.

Explainer: Red shift and Blue shift Redshift and blueshift describe the change in the frequency of a light wave depending on whether an object is moving towards or away from us. When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift.

 

Explainer: Cosmic Microwave Background The cosmic microwave background (CMB) is a faint, pervasive radiation that permeates the entire universe in all directions. It is often regarded as the “afterglow” of the Big Bang, that marked the beginning of our universe. It can’t be seen with naked eyes, but it is everywhere in the universe. The CMB radiation was first detected in 1964-65 by Arno Penzias and Robert Wilson, for which they were awarded the Nobel Prize in Physics in 1978.

 

STAGES OF STAR FORMATION AND BLACK HOLE

The process of star formation is a complex and fascinating journey, typically observed with in gaseous clouds known as nebulae.

(i) Young stage:

• Giant gas cloud: This is the initial stage, where a star is formed from a giant gas (H, He) and dust cloud, also known as a nebula. These clouds are made up of hydrogen, helium, and other light elements.

• Protostar: This is the earliest stage of star formation. It occurs when a portion of a nebula contracts due to gravity. As the gravitational contraction continues, the temperature at the core of this portion increases, but not enough to initiate nuclear fusion. Protostars are often enveloped in dense gas and dust, making them difficult to observe directly in visible light. However, they can be detected in infrared and radio wavelengths.

Knowledge Base: Nuclear Fusion This is a process in which two or more light atomic nuclei combine under high temperature and pressure to form a heavier atomic nucleus. The energy produced by nuclear fusion is the foundation of the energy emitted by the Sun and other stars. This process is one of the most abundant sources of energy in the universe. Chandrasekhar Limit The Chandrasekhar limit is a fundamental concept in astrophysics, formulated by the Indian-American astrophysicist Subrahmanyan Chandrasekhar in 1930. It defines the maximum mass of a stable white dwarf star, approximately 1.4 times the mass of our Sun (1.4 solar masses). Stars with a mass below the Chandrasekhar limit end their lives as white dwarfs. Stars with a mass above this limit undergo further gravitational collapse, leading to the formation of either neutron stars or black holes, depending on their mass. Understanding the Chandrasekhar limit is essential for studying the life cycle of stars, supernovae, and the formation of compact objects like neutron stars and black holes.

 

• T-Tauri Star: As the protostar continues to contract, it becomes hotter and eventually reaches the stage where nuclear fusion begins, marking the birth of a true star. These young stars are known as T-Tauri stars. They are still surrounded by a circumstellar disk of residual gas and dust from the nebula and are quite unstable, meaning their brightness varies irregularly and significantly.

 

(ii) Mature Star (Stage):

• A mature star is one that has reached the main sequence stage of its stellar evolution. Once the T-Tauri phase ends, the main sequence phase begins. This is the longest stage in a star’s life. During this period, hydrogen in the star’s core is converted into helium through nuclear fusion, releasing energy and causing the star to shine.
• The characteristic of this stage is that the energy produced by fusion in the star’s core balances the gravitational contraction, maintaining the star in equilibrium. As a result, the star takes on a stable, spherical, and luminous form.

(iii) Old Stage – Red Giant / Red Supergiant:

• A star (0.8 and 8 solar masses) maintains its stability through a fine balance between its own gravity, which holds it together, and the outwards pressure from ongoing thermonuclear fusion processes taking place at its core.
• Once a star’s core runs out of hydrogen, however, that state of equilibrium is lost, and the core begins to collapse. As the core collapses, the shell of plasma surrounding the core becomes hot enough to begin fusion through itself. As fusion in this shell begins, the extra heat causes the outer layers of the star expand dramatically, and the surface extends up to several hundred times beyond the former size of the star.

• The energy at the star’s surface becomes far more dissipated, causing the star’s bloated surface to cool, turning from white or yellow to red. A red giant is formed.
• When a more massive star (8 to 15 solar masses) runs out of hydrogen at its core, it forms a red supergiant.

Planetary Nebula (Stage after Red Giant):

• A planetary nebula is a region of cosmic gas and dust formed from the cast-off outer layers of a dying star (red giant).

 

Supernova (Stage after Red Supergiant):

• As a dying star burns its fuel and its surface begins to cool, the outward forces of pressure drop. When the pressure drops low enough in the dying star, gravity suddenly takes over, and the star collapses in just seconds. This collapse produces the explosion, that we call a Supernova.
• Supernovae are dramatic explosions that take place during the final stages of the death of a supermassive star (red supergiant).
• A supernova, the biggest energetic explosion known to occur in the Universe. At its peak, a supernova can be brighter than an entire galaxy and can reach a diameter several light-years across.
• A supernova generates a broad spectrum of electromagnetic radiation, including radio waves, infrared, visible light, ultraviolet, X-rays, and sometimes gamma rays. A hypernova is an extremely energetic supernova, often associated with long-duration gamma-ray bursts (GRBs). Both supernovae and hypernovae play significant roles in the universe, dispersing heavy elements into space, which can contribute to the formation of new stars and planets.

 

White Dwarf (Stage after planetary nebula):

• A white dwarf is an astronomical object that forms as a result of the final stages of a star’s life cycle. When a medium-sized star, such as our Sun, reaches the end of its life and exhausts the hydrogen in its core, it sheds its outer layers through a planetary nebula. The remaining core, which is extremely dense and hot, forms the white dwarf.

• White dwarfs are believed to gradually cool over time and may eventually become black dwarfs, although this process can take billions of years.

Neutron Star and its Types (Stage after Supernova):

• A neutron star is the remaining core of a massive star (red supergiant), once it has exploded (supernova). Except for black holes, neutron stars are the smallest and densest currently known class of stellar objects.
• The core of the star collapses under its own gravity, and the pressure becomes so great that the electrons and protons in the atoms are squeezed together to form neutrons. This process is called Neutronization.
• They are so dense that a ‘sugar cube’-sized object of neutron star material would weigh as much as all of the people on Earth.
• Two other physical properties characterize a neutron star, their fast rotation (or spin) and their strong magnetic field. Astronomers have found different classes of neutron stars based on these properties.

• Some of them are the fastest spinning stars in the Universe (up to hundreds of revolutions per second); they are named pulsars as they generate regular pulses of electromagnetic radiation including radio, visible, X-ray, and gamma-ray wavelengths.
• Another class of neutron stars is known as a magnetar, due to their ultra-strong magnetic field. Heir magnetic field intensity is indeed about 100 thousand millions Tesla, a thousand times than an ordinary neutron star. Magnetars are highly magnetized neutron stars that exhibit bursts of X-rays and gamma rays.

Knowledge Box –Star’s Colours

• Red stars are colder, and white/blue stars are hotter.
• Red Stars/Red Dwarf: Red Dwarfs are typically much older because they burn their fuel slowly and can live for billions to trillions of years.
• White/Blue Stars: These stars are typically younger in cosmic terms because they burn their fuel rapidly and live relatively short lives (millions to hundreds of millions of years).
• In conclusion, red dwarfs are the oldest stars in the universe, potentially surviving for trillions of years, while white/blue stars are much younger but live fast and die young.
• Brown dwarfs (false star) are substellar objects that are too small to sustain nuclear fusion of hydrogen.
• Giant stars, which are more massive, burn through their fuel much faster due to higher rates of nuclear reactions and therefore have shorter lifespans compared to dwarf stars. Low-mass stars like dwarfs can shine for tens of billions of years, while massive stars may live only a few million years.

 

Black Holes (Stage after Supernova):

• Black holes were theorized by Albert Einstein in 1915 in his theory of general relativity. Although the term ‘black hole’ was coined in the mid-1960s by American physicist John Archibald Wheeler.
• A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.

 

Key Features:

• Singularity: At the heart of a black hole lies a singularity where matter is compressed to an infinitely small and dense point.
• Event Horizon: A theoretical boundary around a black hole beyond which no matter, light, or other radiation can escape.
• Accretion Disc: A flat, rotating structure composed of gas, dust, and other debris, located outside of the event horizon.
• Astronomers generally divide black holes into three categories according to their mass:
  • Stellar-mass, Supermassive, Intermediate-mass

Types of Black Holes:

1. Stellar Blackhole:
   • Forms when a very massive red supergiant star runs out of nuclear fuel, causing a supernova. What remains is a stellar black hole.
2. Supermassive Blackhole:
   • These supergiant objects have masses ranging from hundreds of thousands to billions of times the Sun’s mass.
   • Almost every large galaxy, including the Milky Way, has a supermassive black hole at its center.
3. Intermediate Blackhole:
   • These are thought to range from around one hundred to hundreds of thousands of times the Sun’s mass—or tens of thousands.

Knowledge Base: Active Galactic Nuclei (AGN) AGN are extremely energetic regions located at the center of a galaxy. They are characterized by such high energy emissions that they can outshine the rest of the galaxy. This energy is primarily generated by a rotating disk of gas and dust around a supermassive black hole situated at the galaxy’s center. AGN activities can vary and include different types such as quasars, blazars, and Seyfert galaxies, depending on their emission patterns, sizes, and energy levels. These are all examples of different types of AGN that can be observed across various radiation bands, such as radio, infrared, optical, X-ray, and gamma-ray. The study of AGN is crucial in astrophysics as it provides insights into galaxy evolution, black hole behavior, and the structure of the universe. The black hole at the center of an AGN can have a mass equivalent to millions or billions of solar masses. The energy emitted by AGN is among the most powerful energy sources in the universe. Quasars and Blazars Quasars and Blazars are extremely bright and energetic active galactic nuclei (AGN) located in the distant universe. They shine due to the enormous amounts of energy emitted by radiation jets from the supermassive black hole at their center. If the radiation jets are directly pointed towards us, the astrophysics object is referred to as a Blazar.

 

Cepheids

• Cepheids, also called Cepheid Variables, are stars which brighten and dim periodically. Cepheids are pulsating stars, meaning they expand and contract periodically, causing their brightness to vary in a regular and predictable manner. The changes in their brightness occur due to the expansion and contraction of their outer layers, which affects the amount of emitted light.

Gamma-Ray Bursts (GRBs)

• Gamma-ray bursts (GRBs) are short-lived bursts of gamma-ray light, the most energetic form of light. Lasting anywhere from a few milliseconds to several minutes, GRBs coincide with supernova and hypernova events.
• Gamma-ray bursts are the most luminous explosions in the cosmos. Astronomers think most occur when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole.

Recent Updates: ETH Project i. In 2019 – The scientists at Event Horizon Telescope (ETH) Project (a group of 8 radio telescopes used to detect radio waves from space) released the first-ever image of a Black Hole in the center of galaxy Messier 87. ii. In May 2022, scientists from the ETH facility revealed the first image of the black hole named Sagittarius A* at the center of our galaxy—the Milky Way.

 

Explainer: White Hole and Wormholes White Hole A white hole is a theoretical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light, and information can escape from it. While black holes have an event horizon from which nothing can escape, white holes would have an event horizon that prevents anything from entering. They are a consequence of the equations of general theory of relativity, but their existence has not been confirmed by observations. Like black holes, white holes are believed to have singularities at their cores. Wormholes Also known as “Einstein-Rosen Bridge,” these are a hypothetical tunnel that would connect two points in space-time.

 

Theory of Relativity

• The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively.
• Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature

General Theory of Relativity It holds that what we perceive as the force of gravity arises from the curvature or warping of space and time. The more massive an object, the more it warps the space around it.

Gravitational Lensing

Gravitational lensing is an effect of Einstein’s theory of general relativity—simply put, mass bends light.

• The gravitational field of a massive object will extend far into space and cause light rays passing close to that object (and through its gravitational field) to be bent and refocused somewhere else.
• The more massive the object, the stronger its gravitational field and hence the greater the bending of light rays.

• An Einstein ring is created when light from a galaxy or star passes by a massive object en route to the Earth. Due to gravitational lensing, the light is diverted, making it seem to come from different places. If source (S), lens (L), and observer (O) are all in perfect alignment, the light appears as a ring.

• The Einstein Cross is an astronomical phenomenon that occurs as a result of gravitational lensing. It is called the Einstein Cross because it appears as four images of the same astronomical object arranged in the shape of a cross. This event happens when a distant source object (such as a quasar) is aligned with a galaxy or a group of galaxies situated between the source object and Earth. The gravitational field of the intervening galaxy or galaxy group bends the light coming from the source object.

 

Gravitational Waves

• A gravitational wave is an invisible ripple in space. Gravitational waves travel at the speed of light. These waves squeeze and stretch anything in their path as they pass by.
• They are tiny perturbations in space-time that ripple outwards from great disturbances like, for instance, two black holes colliding or orbiting, colliding neutron stars, exploding stars such as supernovas, or the birth of the universe.
• Spacetime – Einstein had proven that space and time were not independent entities but had to be woven together as Spacetime.

 

Explainer: Kilonova Explosion A kilonova explosion is an astronomical event that occurs when two neutron stars or a neutron star and a black hole merge. This process releases a tremendous amount of energy and newly formed heavy elements into space in a massive explosion. The merger process creates a significant disturbance in space-time, resulting in the emission of gravitational waves.

 

Explainer: How are gravitational waves detected? In 2015, scientists detected gravitational waves for the very first time. They used a very sensitive instrument called LIGO (Laser Interferometer Gravitational-Wave Observatory). The Nobel Prize in Physics 2017 was given to Rainer Weiss, Barry C. Barish, and Kip S. Thorne “for decisive contributions to the LIGO detector and the observation of gravitational waves.” They observed the first gravitational waves that actually happened when two black holes crashed into one another. According to scientists’ calculations, the collision happened 1.3 billion years ago. But the ripples didn’t make it to Earth until 2015. So, when a gravitational wave passes by Earth, it squeezes and stretches space. LIGO can detect this squeezing and stretching. LIGO observatory has two “arms” that are 4 kilometers long. A passing gravitational wave causes the length of the arms to change slightly. The observatory uses lasers, mirrors, and extremely sensitive instruments to detect these tiny changes.

 

Recent Updates: LIGO India LIGO-India will be built by the Department of Atomic Energy (DAE) and the Department of Science and Technology (DST), with a memorandum of understanding with the U.S. National Science Foundation and several national and international research institutions. LIGO-India will be the third of its kind, made to the exact specification of the twin Laser Interferometer Gravitational-Wave Observatories (LIGO) in Louisiana and Washington in the USA. LIGO project is India’s biggest scientific facility and most advanced cutting edge technology at large scale that will join the ongoing global project to probe the universe by detecting and studying gravitational waves. Recently, Cabinet approved LIGO-India, gravitational-wave detector to be built in Hingoli district, Maharashtra at an estimated cost of Rs 2,600 crore, to be completed by 2030. Other probe related to gravitational waves – Virgo in Italy/France, GEO600 in Germany KAGRA in Japan, LISA Pathfinder and Laser Interferometer Space Antenna (LISA) and Evolved- LISA (e-LISA)- ESA.

 

DARK MATTER AND DARK ENERGY

• The Nobel Prize in Physics 2019 was awarded to James Peebles “for contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos.”
• Using his theoretical tools and calculations, James Peebles was able to interpret dark energy and matter trace from the infancy of the universe and discover new physical processes.
• The results showed us a universe in which just 5% of its content is known, the matter which constitutes stars, planets, trees – and us. The rest, 95%, is unknown dark matter (26%) and dark energy (69%).
• According to Peebles – while dark matter attracts and holds galaxies together, dark energy repels and causes the expansion of our universe.

• Dark matter is a kind of matter that we cannot see or touch, but we know it exists because it has gravity. It is called “dark” because it does not interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation. This makes it difficult to detect directly. However, we can infer the existence of dark matter from its gravitational effects.
• In the discovery of Peebles, he found something shocking: the expansion of the universe was actually speeding up, not slowing down. This meant that there was some unknown force that was overcoming gravity and pushing everything apart. This force is what we call Dark Energy.

 

Experimental efforts for understanding of dark energy and matter:

• Researchers are conducting experiments using cutting-edge technologies to directly detect dark matter particles. Particle colliders like the Large Hadron Collider (LHC) recreate the conditions of the early universe to produce and potentially detect dark matter particles. Various subatomic particle observatories are also working for dark matter observation.

 

PARTICLE PHYSICS: INTRODUCTION

Standard Model of Physics

• The Standard Model of physics is a theoretical framework that describes the fundamental particles, their interactions and forces that make up the universe. It lists the fundamental particles that make up the atoms that further make up the chemical elements. These particles cannot be broken down into any smaller pieces.
• It is a widely accepted theory in the field of particle physics and has been tremendously successful in explaining and predicting a wide range of phenomena.
• Developed in the early 1970s, it has successfully explained almost all experimental results and precisely predicted a wide variety of phenomena.

The Standard Model Components

• The Standard Model has a defined number of key particles: elementary and composite.
• Elementary particles are fermions (quarks, leptons), gauge bosons, and scalar bosons. These particles then join together to create more well-known particles, such as the neutron and the proton. Such particles are known as composite particles, as they are composed of two or more of these elementary particles.

• The fermions: These are the particles that make up matter. There are six types of quarks: up quarks, down quarks, charm quarks, strange quarks, top quarks, and bottom quarks. There are also six types of leptons: electrons, muons, tau, and their associated neutrinos.
• The gauge bosons: These are the particles that carry the forces of nature. In the Standard Model, gauge bosons are force carriers. They mediate the strong, weak, and electromagnetic fundamental interactions. There are four types of bosons: photons, gluons, W and Z bosons, and the Higgs boson.
  • Photon: It mediates the electromagnetic force.
  • W and Z bosons: They mediate the weak nuclear force.
  • Gluons: They mediate the strong nuclear force.
  • Higgs boson: The Higgs boson is the fundamental particle associated with the Higgs field, a field that gives mass to other fundamental particles.

Note: The Standard Model does not explain gravity.

 

Experimental Confirmations

The predictions of the Standard Model have been extensively tested and confirmed through experiments conducted at particle accelerators, such as the Large Hadron Collider (LHC) and neutrinos observatories.

1. Large Hadron Collider (LHC)
   • The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. It first started up on 10 September 2008 and remains the latest addition to the European Organization for Nuclear Research (CERN)’s accelerator complex.
   • The LHC consists of a 27-kilometer ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes — two tubes kept at ultrahigh vacuum. In 2012, it confirmed the presence of the Higgs boson — the “God particle.”
   • Major objectives of LHC:
     • Higgs boson discovery, search for new particles, understanding fundamental forces, matter and antimatter asymmetry, search for dark matter, and more.

1. Neutrinos Observatories

The largest neutrino detectors in the world.

1. • IceCube at the South Pole (Antarctica).
   • ANTARES in the Mediterranean Sea
   • Baikal-GVD (Gigaton Volume Detector) in Russia

• These facilities study in detail the elusive fundamental particles called neutrinos and possibly determine their sources.

Need for studying:

• Neutrinos are elementary particles that have no electric charge and very little mass. They are so weakly interacting that they can pass through the Earth without being stopped.
• Neutrinos are produced in nuclear reactions, such as those that occur in the sun and stars. They are also produced in the decay of radioactive elements. Neutrinos are very mysterious particles, and we still don’t know a lot about them.
• But the study of these particles aids scientists’ understanding of the origins of the universe since some neutrinos were formed during the Big Bang, while others continue to be formed as a result of supernova explosions or because of nuclear reactions in the Sun.
• It is possible that a large fraction of the dark matter of the universe consists of primordial, Big Bang neutrinos. The 2002 and 2015 Physics Nobel Prizes were related to research on neutrinos.

Note: Stalled due to environmental concerns – Indian Neutrino Observatory (INO) – Tamilnadu

It is jointly funded by the Dept. of Atomic Energy and the Dept. of Science and Technology.

Important Indian Astronomical Observatories: ARIES (Aryabhata Research Institute of Observational Sciences) installed at Nainital, Uttarakhand. Kodaikanal Solar Observatory: Tamilnadu. Major Atmospheric Cherenkov Experiment Telescope (MACE) in Hanle, Ladakh. Vainu Bappu Observatory (VBO): Tamil Nadu. The Giant Metrewave Radio Telescope, Pune (India’s largest telescope).

 

 

PREVIOUS YEAR QUESTIONS

1. Which one of the following countries has its own Satellite Navigation System? (2023)
   (a) Australia
   (b) Canada
   (c) Israel
   (d) Japan
2. If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth? (2022)

1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.

Select the correct answer using the code given below:
(a) 1, 2, 4 and 5 only
(b) 2, 3, 6 and 7 only
(c) 1, 3, 4, 6 and 7 only
(d) 1, 2, 3, 4, 5, 6 and 7

3. Which one of the following is a reason why astronomical distances are measured in light-years? (2021)
   (a) Distances among stellar bodies do not change.
   (b) Gravity of stellar bodies does not change.
   (c) Light always travels in a straight line.
   (d) Speed of light is always the same.
4. For the measurement/estimation of which of the following, satellite images/remote sensing data are used? (2019)

1. Chlorophyll content in the vegetation of a specific location
2. Greenhouse gas emissions from rice paddies of a specific location
3. Land surface temperatures of a specific location

Select the correct answer using the code given below:
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3

5. With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements: (2018)

1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits.
2. IRNSS covers entire India and about 5500 sq. km beyond its borders.
3. India will have its own satellite navigation system with full global coverage by the middle of 2019.

Which of the statements given above is/are correct?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) None

6. The GoI is pushing smartphone makers to enable support for its NavIC navigation system in new devices. In which of the following areas can GPS technology be used? (2018)

1. Mobile phone operations
2. Banking operations
3. Controlling the power grids

Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

7. With reference to India’s satellite launch vehicles, consider the following statements: (2018)

1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3
(c) 1 and 2
(d) 3 only

8. With reference to ‘Astrosat’, the astronomical observatory launched by India, which of the following statements is/are correct? (2016)

1. Other than USA and Russia, India is the only country to have launched a similar observatory into space.
2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth.

Select the correct answer using the code given below:
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

9. Consider the following statements: (2016)

1. The Mangalyaan launched by ISRO is also called the Mars Orbiter Mission.
2. It made India the second country to have a spacecraft orbit the Mars after USA.
3. It is India’s only country to be successful in making its spacecraft orbit the Mars in its very first attempt.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3

10. In which of the following activities are Indian Remote Sensing (IRS) satellites used? (2015)

1. Assessment of crop productivity
2. Locating underwater resources
3. Mineral exploration
4. Telecommunications
5. Traffic studies

Select the correct answer using the code given below:
(a) 1, 2 and 3 only
(b) 4 and 5 only
(c) 1 and 2 only
(d) 1, 2, 3, 4 and 5

11. Which of the following pairs is/are correctly matched? (2014)

Spacecraft	Purpose
Cassini-Huygens	Orbiting the Venus and transmitting data to Earth
Messenger	Mapping and investigating the Mercury
Voyager 1 and 2	Exploring the outer solar system

Select the correct answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

12. An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth (2011)
    (a) Does not exist at such distance
    (b) Is neutralized by the attraction of the moon
    (c) Provides the necessary speed for its steady motion
    (d) Provides the necessary acceleration for its motion
13. Satellites used for telecommunication relay are kept in a geostationary orbit. A satellite is said to be in such an orbit when: (2011)

1. The orbit is geosynchronous.
2. The orbit is circular.
3. The orbit lies in the plane of the Earth’s equator.
4. The orbit is at an altitude of 22,236 km.

Select the correct answer using the codes given below:
(a) Only 1, 2 and 3
(b) Only 1, 3 and 4
(c) Only 2 and 4
(d) 1, 2, 3 and 4

14. Consider the following statements: The satellite Oceansat-2 launched by India helps in: (2010)

1. Estimating the water vapour content in the atmosphere.
2. Predicting the onset of monsoons.
3. Monitoring the pollution of coastal waters.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3

15. In the context of space technology, what is “Bhuvan” recently in the news? (2010)
    (a) A mini satellite launched by ISRO for promoting the distance education in India
    (b) The name given to the next Moon Impact Probe, for Chandrayaan-II
    (c) A geoportal of ISRO with 3D imaging capabilities of India
    (d) A space telescope developed by India
16. ISRO successfully conducted a rocket test using cryogenic engines in the year 2007. Where is the test stand used for the purpose located? (2008)
    (a) Balasore
    (b) Thiruvananthapuram
    (c) Mahendragiri
    (d) Karwar
17. The location of the space organisation unit has been marked in the given map as 1, 2, 3, and 4. Match these units with the list given below and select the correct answer using the codes given below: (2007)
18. ISRO
    B. IIRS
    C. NRSC
    D. SAC

Codes:
(a) A-4; B-1; C-2; D-3
(b) A-1; B-4; C-3; D-2
(c) A-1; B-4; C-2; D-3
(d) A-4; B-1; C-3; D-2

18. Consider the following statements: (2007)

1. In the year 2006, India successfully tested a full-fledged cryogenic stage in rocketry.
2. After USA, Russia, and China, India is the only country to have acquired the capability for the use of cryogenic stage in rocketry.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

19. Assertion (A): Artificial satellites are always launched from the earth in the eastward direction.
    Reason (R): The earth rotates from west to east and so the satellite attains the escape velocity. (2002)

Select the correct answer:
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true

20. Cryogenic engines find applications in: (1995)
    (a) Sub-marine propulsion
    (b) Frost-free refrigerators
    (c) Rocket technology
    (d) Research in superconductivity
21. With reference to radioisotope thermoelectric generators (RTGs), consider the following statements: 2024
22. RTGs are miniature fission reactors.
23. RTGs are used for powering the onboard systems of spacecrafts.
24. RTGs can use Plutonium-238, which is a by-product of weapons development.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

22. Consider the following pairs: 2023

Objects in space:   Description   

1. Cepheids: Giant clouds of dust and gas in space
2. Nebulae: Stars which brighten and dim periodically
3. Pulsars:  Neutron stars that are formed when massive stars run out of fuel and collapse

How many of the above pairs are correctly matched?

1. a) Only one
2. b) Only two
3. c) All three
4. d) None
5. The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometers long, with lasers shining between the craft. The experiment in question refers to: (2020)
   (a) Voyager-2
   (b) New Horizons
   (c) LISA Pathfinder
   (d) Evolved LISA
6. Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation? (2019)
   (a) ‘Higgs boson particles’ were detected.
   (b) ‘Gravitational waves’ were detected.
   (c) Possibility of inter-galactic space travel through ‘wormhole’ was confirmed.
   (d) It enabled the scientists to understand ‘singularity.’
7. Consider the following phenomena: (2018)

1. Light is affected by gravity.
2. The Universe is constantly expanding.
3. Matter warps its surrounding space-time.

Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3

26. The terms ‘Event Horizon,’ ‘Singularity,’ ‘String Theory’ and ‘Standard Model’ are sometimes seen in the news in the context of: (2017)
    (a) Observation and understanding of the Universe
    (b) Study of the solar and the lunar eclipses
    (c) Placing satellites in the orbit of the Earth
    (d) Origin and evolution of living organisms on the Earth
27. What is the purpose of ‘evolved Laser Interferometer Space Antenna (eLISA)’ project? (2017)
    (a) To detect neutrinos
    (b) To detect gravitational waves
    (c) To detect the effectiveness of missile defense system
    (d) To study the effect of solar flares on our communication systems
28. In the context of modern scientific research, consider the following statements about ‘IceCube,’ a particle detector located at South Pole, which was recently in the news: (2016)

1. It is the world’s largest neutrino detector, encompassing a cubic kilometer of ice.
2. It is a powerful telescope to search for dark matter.
3. It is buried deep in the ice.

Which of the statement(s) given above is/are correct?
(a) Only 1
(b) Only 2 and 3
(c) Only 1 and 3
(d) 1, 2 and 3

29. The efforts to detect the existence of Higgs boson particle have become frequent news in the recent past. What is/are the importance/importance of discovering this particle? (2013)

1. It will enable us to understand as to why elementary particles have mass.
2. It will enable us in the near future to develop the technology of transferring matter from one point to another without traversing the physical space between them.
3. It will enable us to create better fuels for nuclear fission.

Select the correct answer using the codes given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

30. Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of the universe? (2012)

1. Detection of microwaves in space
2. Observation of redshift phenomenon in space
3. Movement of asteroids in space
4. Occurrence of supernova explosions in space

Select the correct answer using the codes given below:
(a) 1 and 2
(b) 2 only
(c) 1, 3 and 4
(d) None of the above can be cited as evidence

31. Consider the following statements: 2024

Statement-I: Giant stars live much longer than dwarf stars.

Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions.

Which one of the following is correct in respect of the above statements?

1. Both Statement-I and Statement-II are correct and Statement-II explains Statement-1
2. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
3. Statement I is correct, but Statement II is incorrect
4. Statement I is incorrect, but Statement II is correct
5. A team of scientists at Brookhaven National Laboratory included those from India created the heaviest anti-matter (anti-helium nucleus). What is/are the implication/implications of the creation of anti-matter? 2012
6. It will make mineral prospecting and oil exploration easier and cheaper.
7. It will help prove the possibility of the existence of stars and galaxies made of anti-matter.
8. It will help understand the evolution of the universe.

Select the correct answer using the codes given below:

1. 1 only
2. 2 and 3 only
3. 3 only
4. 1, 2 and 3

33.. Who of the following scientists proved that the stars with mass less than 1.44 times the mass of the Sun end up as White Dwarfs when they die? 2009
(a) Edwin Hubble
(b) S. Chandrashekhar
(c) Stephen Hawking
(d) Steven Weinberg

34. India-based Neutrino Observatory is included by the Planning Commission as a mega science project under the 11th Five-Year Plan. In this context, consider the following statements: 2010

1. Neutrinos are chargeless elementary particles that travel close to the speed of light.
2. Neutrinos are created in nuclear reactions of beta decay.
3. Neutrinos have a negligible, but nonzero mass.
4. Trillions of Neutrinos pass through the human body every second.

Which of the statements given above are correct?
(a) 1 and 3 only
(b) 1, 2 and 3 only
(c) 2, 3 and 4
(d) 1, 2, 3 and 4

 

Answer Key:

Question	1	2	3	4	5	6	7	8	9	10
Answer	D	C	D	D	A	D	A	D	C	A
Question	11	12	13	14	15	16	17	18	19	20
Answer	B	D	A	D	C	C	D	A	C	C
Question	21	22	23	24	25	26	27	28	29	30
Answer	B	A	D	B	D	A	B	D	A	a
Question	31	32	33	34
Answer	D	B	B	D

 

 

PRELIMS PRACTICE QUESTIONS

1. Consider the following statements regarding Dark Matter and Dark Energy:

1. The nature of Dark Matter is attractive while that of Dark Energy is repulsive.
2. In the universe around 28% is Dark Energy while 67% is Dark Matter.

Which among the above given statement/s is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

 

1. Consider the following statements regarding NISAR mission:

1. The purpose of the mission is to determine earth changes in three disciplines: ecosystems, deformation, and cryosphere sciences.
2. It is a collaboration between Indian Space Research Organisation (ISRO) and European Space Agency (ESA).
3. It will be launched from the Satish Dhawan Space Centre into Sun-synchronous low earth orbit (LEO) with a 12-day repeat cycle.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 3 only
(c) 2 and 3 only
(d) 1 and 3 only

 

1. Consider the following pairs:

Type of Boson Particle	Type of Force it Mediates
1. Photon	Electromagnetic force
2. W and Z bosons	Strong nuclear force
3. Gluons	Weak nuclear force

How many of the above-given pairs is/are correctly matched?
(a) One pair only
(b) Two pairs only
(c) All three pairs
(d) None

1. Consider the following statements regarding James Webb Space Telescope (JWST):

1. JWST will orbit in the halo orbit around the Sun-Earth gravity-neutral point Lagrange point 1 (L1).
2. Like the Hubble Space Telescope, the observations will be captured in the visible and ultraviolet range of the electromagnetic spectrum only.
3. It is a joint venture of NASA, European Space Agency, and Canadian Space Agency.

Which among the above-given statement/s is/are incorrect?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All of the above

 

1. Regarding the utilization of satellites for navigation services, evaluate the following assertions concerning the “Navigation with Indian Constellation (NavIC)” developed by the Indian Space Research Organization (ISRO):

1. NavIC comprises a constellation of seven satellites, with three positioned in geostationary orbit.
2. It offers Standard Position Service (SPS) catering to civilian users and Restricted Service (RS) designated for strategic users
3. NavIC’s coverage area encompasses regions beyond India’s borders.

How many of the above statements are correct?
(a) Only one
(b) Only two
(c) All three
(d) None

 

1. Consider the following statements regarding Blackholes and Whiteholes:

1. While Blackholes have been discovered recently, Whiteholes are only theoretically proven so far.
2. The theory of general relativity given by Albert Einstein provides justification for their existence.
3. No matter can escape from both Blackholes and Whiteholes.

Which of the above-given statements are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All of the above

1. These are a specific type of stars which are highly magnetized and have their own rotation. They also emit beams of electromagnetic radiation. If one of these beams points towards Earth, we observe periodic pulses of radiation. These also serve as incredibly precise cosmic clocks as their rotation periods are so stable that they can be used to measure time with extraordinary accuracy.
   (a) White Dwarf
   (b) Pulsars
   (c) Quasars
   (d) Supernova

 

1. With reference to launch vehicles developed by ISRO, consider the following statements:

1. PSLV-XL utilizes both solid and liquid propulsion stages with six strap-on boosters for additional thrust during its initial flight.
2. LVM3 features an indigenously developed cryogenic upper stage and is ISRO’s heaviest rocket.
3. SSLV employs three solid propulsion stages and is capable of launching mini and micro satellites to Geostationary Orbits.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2, and 3

1. Which of the following is not the objective of ADITYA – L1?
   (a) A deeper understanding of coronal heating and solar wind acceleration.
   (b) A deeper understanding of magnetic fields of neutron stars.
   (c) A deeper understanding of solar wind distribution and temperature anisotropy.
   (d) A deeper understanding of Coronal Mass Ejection (CME), flares, and near-earth spacel weather.

 

1. Consider the following statements about Cosmic Microwave Background:

1. It is regarded as the afterglow of the Big-Bang.
2. It can be observed with the naked eyes.
3. Its precise measurements have yielded important insights into the composition, age, and geometry of the universe.

Which among the above-given statements are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) All of the above

 

Answer Key:

Question	1	2	3	4	5	6	7	8	9	10
Answer	a	d	a	a	c	a	b	a	b	c

 

MAINS PREVIOUS YEARS QUESTIONS

1. What are asteroids? How real is the threat of them causing extinction of life? What strategies have been developed to prevent such a catastrophe? (Answer in 250 words) [2024]
2. What is the main task of India’s third moon mission which could not be achieved in its earlier mission? List the countries that have achieved this task. Introduce the subsystems in the spacecraft launched and explain the role of the ‘Virtual Launch Control Centre’ at the Vikram Sarabhai Space Centre which contributed to the successful launch from Sriharikota.   (Answer in 250 words) [2023]
3.  Launched on 25th December 2021, James Webb Space Telescope has been much in the news since then. What are its key features which make it superior to its predecessor space telescopes? What are the key potential benefits does it hold for the human race? (250 Words) [2022]
4.  What is India’s plan to have its own space station and how will it benefit our space programme? (150 Words) [2019]
5. India has achieved remarkable successes in unmanned space missions including the Chandrayaan and Mars Orbiter Mission, but has not ventured into manned space missions. What are the main reasons for it? (150 Words) [2017]
6. How does the Lunar Mission of NASA help to understand the origin and evolution of the Earth? (150 Words) [2017]
7. What do you understand by ‘Standard Positioning Systems’ and ‘Precision Positioning Systems’ in the GPS era? Discuss the advantages India has from its ambitious IRNSS programme. (150 Words) [2017]
8. Discuss India’s achievements in the field of Space Science and Technology. How has the application of this technology helped India in its socio-economic development? (250 Words) [2016]

 

MAINS PRACTICE QUESTIONS

 

1. Discuss the opportunities and challenges associated with promoting private sector participation in the space sector in developing countries, focusing on India’s efforts and experiences.

(150 Words)

1. Discuss ISRO’s achievements in the field of Space Science and Technology. How the application of this technology has helped India in its socio-economic development?

(150 Words)

1. Recently, NASA and ISRO have tracked the most intense geomagnetic storm in decades. Discuss the phenomenon of geomagnetic storms and their impact on Earth’s environment. How does the Aditya-L1 mission contribute to the study and prediction of geomagnetic storms?

(250 Words)