Space Technology Archives

21. The term ‘Goldilocks Zone’ is often seen in the news in the context of

The term ‘Goldilocks Zone’ is often seen in the news in the context of

the limits of habitable zone above the surface of the Earth

regions inside the Earth where shale gas is available

search for the Earth-like planets in outer space

search for meteorites containing precious metals

This question was previously asked in

UPSC IAS – 2015

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The term ‘Goldilocks Zone’, also known as the habitable zone or “potentially habitable zone,” refers to the range of distance from a star where a planet’s surface temperature might allow for liquid water to exist, given sufficient atmospheric pressure. The search for the Goldilocks Zone around other stars is directly related to the search for exoplanets (planets outside our solar system) that could potentially harbor life as we know it.

– The Goldilocks Zone is the region around a star where liquid water could potentially exist on a planet’s surface.
– Liquid water is considered essential for life as we know it.
– The concept is crucial in astrobiology and the search for exoplanets that might be habitable.

The term is derived from the fairy tale “Goldilocks and the Three Bears,” where Goldilocks chose the porridge, chair, and bed that were “just right.” Similarly, the Goldilocks Zone is “just right” in terms of temperature for liquid water.

22. Which of the following pairs is/are correctly matched? Spacecraft

Which of the following pairs is/are correctly matched?

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

Select the correct answer using the code given below.

1 only

2 and 3 only

1 and 3 only

1, 2 and 3

This question was previously asked in

UPSC IAS – 2014

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The correct answer is B) 2 and 3 only. Let’s examine each pair:
1. Cassini-Huygens: This was a joint NASA/ESA/ASI mission to study Saturn and its moon Titan. It did not orbit Venus. This pair is incorrectly matched.
2. Messenger: This was a NASA mission to study the planet Mercury. The name stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. This pair is correctly matched.
3. Voyager 1 and 2: These are NASA probes launched in 1977 to explore the outer solar system, specifically Jupiter, Saturn, Uranus, and Neptune. This pair is correctly matched.

Space missions are designed with specific target celestial bodies or regions. Correctly identifying the purpose of famous spacecraft is important for general knowledge about space exploration.

Cassini-Huygens arrived at Saturn in 2004 and orbited it until 2017. The Huygens probe landed on Titan in 2005. Messenger orbited Mercury from 2011 until it was deliberately crashed into the surface in 2015. Voyager 1 and 2 are now in interstellar space, continuing to send back data.

23. In Sun-Earth system, the distance between Lagrange points L2 and L3 is

In Sun-Earth system, the distance between Lagrange points L2 and L3 is about

15 lakh kilometre

30 lakh kilometre

16 crore kilometre

32 crore kilometre

This question was previously asked in

UPSC CAPF – 2024

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Lagrange points L1, L2, and L3 for the Sun-Earth system lie on the line connecting the Sun and the Earth. L1 and L2 are located approximately 1.5 million kilometers (or 0.01 AU) from Earth. L1 is between the Sun and Earth, and L2 is beyond Earth away from the Sun. L3 is on the opposite side of the Sun from Earth, roughly at the same distance from the Sun as Earth (approx 1 AU). The distance between L2 and L3 is approximately the distance from L2 to Earth (~1.5M km) + the distance from Earth to the Sun (~150M km) + the distance from the Sun to L3 (~150M km). This sum is approximately 1.5M km + 150M km + 150M km = 301.5M km. This is equivalent to 30.15 crore kilometers. Option D, 32 crore kilometre, is the closest value among the choices.

– L1, L2, and L3 are collinear Lagrange points in a two-body system.
– For the Sun-Earth system, L1 and L2 are about 1.5 million km from Earth.
– L3 is roughly 1 AU (approx 150 million km) from the Sun, on the opposite side of Earth.
– The distance between L2 and L3 is approximately L2-Earth distance + Earth-Sun distance + Sun-L3 distance.

While L3 is roughly 1 AU from the Sun, its exact location is slightly closer or farther depending on the mass distribution and other orbital parameters, but approximately 1 AU. The total distance L2 to L3 is therefore approximately 0.01 AU + 1 AU + 1 AU = 2.01 AU. Since 1 AU is about 150 million km, 2.01 AU is about 301.5 million km (30.15 crore km). Option D (32 crore km) is the best fit among the given choices.

24. NISAR satellite is manufactured jointly by Indian Space Research Organ

NISAR satellite is manufactured jointly by Indian Space Research Organisation and:

Japan Aerospace Exploration Agency

National Aeronautics and Space Administration

Russian Federal Space Agency

European Space Agency

This question was previously asked in

UPSC CAPF – 2023

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The NISAR satellite is a joint Earth observation mission developed by the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) of the United States. The acronym NISAR stands for NASA-ISRO Synthetic Aperture Radar.

– NISAR is a collaborative project between the space agencies of India (ISRO) and the USA (NASA).
– It is designed to map the Earth’s surface using advanced radar technology (Synthetic Aperture Radar).
– The mission aims to study ecosystems, ice mass, vegetation biomass, sea level rise, groundwater, and natural hazards like earthquakes, tsunamis, volcanoes, and landslides.

NISAR is expected to be one of the most expensive Earth science satellites ever built. It will use two radar frequencies (L-band and S-band) to provide detailed information about the Earth’s land and ice surfaces. The satellite was assembled and underwent testing in India before being shipped to the US for final integration and launch preparations.

25. The term ‘Sagittarius A*’, sometimes mentioned in news, refers to

The term ‘Sagittarius A*’, sometimes mentioned in news, refers to

a supermassive black hole in our Milky Way Galaxy

two giant black holes spiralling around each other several light- years away from the Earth

a Supernova explosion seen in real time for the first time ever by scientists

a huge asteroid that passed by very close to the Earth

This question was previously asked in

UPSC CAPF – 2022

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Sagittarius A* is the name given to the supermassive black hole located at the center of our Milky Way galaxy. It is approximately 26,000 light-years away from Earth. It has been a subject of intense study by astronomers, and its image was captured for the first time by the Event Horizon Telescope collaboration in 2022.

Supermassive black holes are found at the centers of most large galaxies. Sagittarius A* has a mass equivalent to about four million times that of our Sun.

The Event Horizon Telescope is a global network of radio telescopes that work together to form a virtual Earth-sized telescope capable of imaging black holes. They previously captured the image of the black hole in galaxy M87.

26. Which one of the following aerospace companies designed and manufactur

Which one of the following aerospace companies designed and manufactured ‘Falcon 9’, a reusable rocket?

Blue Origin

Boeing

Lockheed Martin

SpaceX

This question was previously asked in

UPSC CAPF – 2022

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‘Falcon 9’ is a reusable, two-stage-to-orbit medium-lift launch vehicle designed and manufactured by SpaceX.

SpaceX is a prominent American aerospace manufacturer and space transportation services company founded by Elon Musk. It is known for developing reusable rocket technology, including the Falcon 9 and Falcon Heavy launch vehicles, and the Starship spacecraft.

Blue Origin is another American aerospace company founded by Jeff Bezos, also working on reusable rocket technology (like the New Shepard and New Glenn). Boeing and Lockheed Martin are major aerospace and defence companies involved in various space programs, including the United Launch Alliance (ULA) joint venture, but Falcon 9 is specifically a SpaceX product.

27. Consider the following statements: 1. Aluminium powder is used as a

Consider the following statements:

1. Aluminium powder is used as a solid fuel for rocket engines.
2. Compared to liquid fuel propelled rocket engines, the thrust per amount of fuel burned is higher in solid fuel propelled rocket engines.

Which of the statements given above is/are correct?

1 only

2 only

Both 1 and 2

Neither 1 nor 2

This question was previously asked in

UPSC CAPF – 2022

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Statement 1: Aluminium powder is used as a solid fuel for rocket engines. This statement is correct. Aluminium is a common fuel ingredient in composite solid rocket propellants. It increases the propellant’s energy density and burning temperature, contributing significantly to performance.
Statement 2: Compared to liquid fuel propelled rocket engines, the thrust per amount of fuel burned is higher in solid fuel propelled rocket engines. This statement is incorrect. “Thrust per amount of fuel burned” is related to specific impulse (Isp), which measures the efficiency of a rocket engine. High-performance liquid propellants (like liquid hydrogen and liquid oxygen) generally yield higher specific impulse than typical solid propellants. A higher specific impulse means more thrust is produced per unit of propellant mass flow rate, or equivalently, a given amount of fuel produces thrust for a longer time. While solid rockets can provide high thrust for short periods and are simpler, their efficiency in terms of thrust generated per unit mass of fuel consumed is usually lower than optimized liquid systems.

– Aluminium powder is a common ingredient in solid rocket propellants, acting as a fuel.
– Specific impulse (Isp) is a measure of rocket engine efficiency, representing thrust per unit weight flow rate of propellant, or exhaust velocity.
– Liquid propellants, especially cryogenic ones like LH2/LOX, generally achieve higher specific impulse than solid propellants.
– Higher specific impulse means more thrust generated per amount of fuel burned (by mass).

Solid rocket motors are valued for their simplicity, reliability, and high thrust density (thrust per unit volume), making them suitable for applications where rapid acceleration and compact design are critical (e.g., missiles, strap-on boosters). However, their lower specific impulse and lack of thrust control or shut-off capability are disadvantages compared to liquid rocket engines for many applications, particularly for upper stages or missions requiring precise velocity control.

28. Which one among the following statements about the GSLV-D5 launched by

Which one among the following statements about the GSLV-D5 launched by India on 5 January 2014 is not true ?

It puts India in an elite club with Russia, USA, China, Japan and France

It uses an indigenously built cryogenic engine

It can place communication satellites into orbit without depending on any other country

It placed INSAT-14 precisely into its orbit

This question was previously asked in

UPSC CAPF – 2014

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The correct option is D, as GSLV-D5 launched GSAT-14, not INSAT-14.

– Statement A is true. With the successful use of its indigenous cryogenic engine, India joined an exclusive group of countries capable of launching heavy communication satellites into geostationary transfer orbit (GTO) using their own cryogenic technology.
– Statement B is true. GSLV-D5 was the first successful flight of the GSLV using the domestically developed cryogenic upper stage (CUS). Previous attempts with the indigenous CUS had failed.
– Statement C is true. The primary objective of developing the GSLV with an indigenous cryogenic engine is to achieve self-reliance in launching communication satellites into GTO, eliminating dependence on foreign launch services for this class of satellites.
– Statement D is false. The satellite successfully placed into GTO by GSLV-D5 on January 5, 2014, was **GSAT-14**, a communication satellite, not INSAT-14.

The GSLV is ISRO’s launch vehicle for placing satellites into Geostationary Transfer Orbit (GTO). The development and successful testing of the indigenous cryogenic engine was a major technological milestone for India’s space program.

29. Consider the following statements about NEOSSat launched by PSLV in Fe

Consider the following statements about NEOSSat launched by PSLV in February 2013 :

1. It is the only space telescope dedicated to searching for asteroids that might have a threat to the earth.
2. It was designed and developed by ISRO.

Which of the statements given above is/are correct?

1 only

2 only

Both 1 and 2

Neither 1 nor 2

This question was previously asked in

UPSC CAPF – 2013

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Statement 1 is correct, while Statement 2 is incorrect.

– NEOSSat (Near Earth Object Surveillance Satellite) was indeed the first space telescope dedicated to searching for and tracking asteroids and space debris that could pose a threat to Earth. It was launched in February 2013.
– NEOSSat was a Canadian satellite mission, developed and operated by the Canadian Space Agency (CSA) and Defence Research and Development Canada (DRDC). ISRO’s PSLV rocket was used to launch the satellite as a co-passenger, but ISRO did not design or develop NEOSSat.

– ISRO’s PSLV-C20 mission on February 25, 2013, successfully launched NEOSSat along with other satellites like SARAL (primary payload), UniBRITE, BRITE-Austria, SAPPHIRE, and TUGSAT-1 from the Satish Dhawan Space Centre, Sriharikota.
– While other space telescopes (like Hubble or Kepler) might observe asteroids, NEOSSat was specifically designed for this dedicated purpose, giving Statement 1 validity in its context.

30. Which one among the following is not a Mars rover?

Which one among the following is not a Mars rover?

Sojourner

Opportunity

Curiosity

Apollo

This question was previously asked in

UPSC CAPF – 2013

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The correct option is D.

– The question asks to identify which of the given options is *not* a Mars rover.
– A) **Sojourner:** This was NASA’s first wheeled vehicle to rove on Mars, landing as part of the Mars Pathfinder mission in 1997. It is a Mars rover.
– B) **Opportunity:** This was one of NASA’s two Mars Exploration Rovers (MER-B), active on Mars from 2004 to 2018. It is a Mars rover.
– C) **Curiosity:** This is NASA’s Mars Science Laboratory (MSL) rover, which landed on Mars in 2012 and is still operational. It is a Mars rover.
– D) **Apollo:** This refers to NASA’s series of missions that landed humans on the Moon between 1969 and 1972. It is a lunar program, not a Mars rover.

Besides these, other notable Mars rovers include Spirit (NASA, MER-A), Perseverance (NASA, part of Mars 2020 mission), and Zhurong (CNSA, part of Tianwen-1 mission).