Space Technology Archives

31. Geostationary satellite completes its one revolution around the earth

Geostationary satellite completes its one revolution around the earth in

[amp_mcq option1=”90 minutes” option2=”24 hours” option3=”30 days” option4=”365 days” correct=”option2″]

This question was previously asked in

UPSC CAPF – 2013

B) 24 hours

A geostationary satellite orbits the Earth at a specific altitude (approximately 35,786 kilometers above the equator) and follows the Earth’s rotation. For a satellite to appear stationary from a point on the Earth’s surface, its orbital period must be exactly equal to the Earth’s sidereal rotation period, which is about 23 hours, 56 minutes, and 4 seconds. For practical purposes and standard options, this is typically rounded to 24 hours. This synchronization allows the satellite to remain over the same geographic location on the equator.

Geostationary satellites are crucial for communication (television, internet), weather monitoring, and navigation (though GPS uses MEO satellites). Their fixed position relative to the ground simplifies the design of ground antennas, which do not need to track the satellite. Geostationary orbits are a specific type of geosynchronous orbit, which has a period equal to the Earth’s rotation period but may not necessarily be inclined zero degrees to the equator.

32. Consider the following statements about the ‘Curiosity’ rover: 1. It

Consider the following statements about the ‘Curiosity’ rover:

1. It is a robotic mission for exploration of the Mars launched by NASA.
2. It is powered by solar energy.

Which of the statements given above is/are correct?

[amp_mcq option1=”1 only” option2=”2 only” option3=”Both 1 and 2″ option4=”Neither 1 nor 2″ correct=”option1″]

This question was previously asked in

UPSC CAPF – 2012

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Statement 1: The Curiosity rover is part of NASA’s Mars Science Laboratory (MSL) mission. It is a robotic mission designed to explore the Gale Crater on Mars as part of NASA’s Mars Exploration Program. This statement is correct. Statement 2: The Curiosity rover is not powered by solar energy. Due to the potential for dust storms and the distance from the Sun, it uses a Radioisotope Thermoelectric Generator (RTG), which provides continuous power by converting the heat from the radioactive decay of plutonium-238 into electricity. This statement is incorrect.

RTGs are often used for long-duration space missions, especially those exploring the outer solar system or surface missions on bodies like Mars where solar power is unreliable or insufficient.

The primary goals of the Curiosity mission include determining if Mars ever had the environmental conditions suitable for microbial life, studying the planet’s geology and climate, and preparing for human exploration.

33. Which of the following statements relating to the planet Venus is/are

Which of the following statements relating to the planet Venus is/are correct ?

1. It is the nearest planet from the Sun.
2. It is only slightly smaller than the Earth.
3. It has no atmosphere.

Select the correct answer using the code given below :

[amp_mcq option1=”1, 2 and 3″ option2=”1 and 3 only” option3=”2 only” option4=”1 and 2 only” correct=”option3″]

This question was previously asked in

UPSC CAPF – 2011

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Statement 2 is correct: Venus is often called Earth’s sister planet because it is only slightly smaller than Earth in size (diameter of Venus is about 12,104 km compared to Earth’s 12,742 km) and mass.

Venus is the second planet from the Sun and has a dense, toxic atmosphere primarily composed of carbon dioxide.

Statement 1 is incorrect: Mercury is the nearest planet to the Sun, followed by Venus, Earth, Mars, etc. Statement 3 is incorrect: Venus has a very thick atmosphere, about 90 times denser than Earth’s atmosphere, leading to extremely high surface temperatures due to a runaway greenhouse effect.

34. Which one of the following is the name given to the lander of Chandray

Which one of the following is the name given to the lander of Chandrayaan-2 ?

[amp_mcq option1=”Vigyan” option2=”Anusandhan” option3=”Pragyan” option4=”Vikram” correct=”option4″]

This question was previously asked in

UPSC NDA-2 – 2019

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The correct option is D) Vikram.

The lander component of India’s Chandrayaan-2 mission was named ‘Vikram’ in honour of Dr. Vikram Sarabhai, widely regarded as the father of India’s space programme. The rover carried inside the lander was named ‘Pragyan’ (meaning ‘wisdom’ in Sanskrit).

Chandrayaan-2 was ISRO’s second lunar exploration mission, launched in July 2019. The mission aimed to soft-land the Vikram lander and deploy the Pragyan rover on the lunar south pole, but communication with the lander was lost just before its planned touchdown.

35. Which one of the following statements about a satellite orbiting aroun

Which one of the following statements about a satellite orbiting around the Earth is correct ?

[amp_mcq option1=”Satellite is kept in orbit by remote control from ground station.” option2=”Satellite is kept in orbit by retro-rocket and solar energy keeps it moving around the Earth.” option3=”Satellite requires energy from solar panels and solid fuels for orbiting.” option4=”Satellite does not require any energy for orbiting.” correct=”option4″]

This question was previously asked in

UPSC NDA-2 – 2017

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Once a satellite is placed into a stable orbit around the Earth, it does not require continuous energy input for orbiting itself. The motion is maintained by the balance between the satellite’s inertia (tendency to keep moving in a straight line) and the gravitational pull of the Earth, which continuously deflects it towards the Earth, causing it to follow a curved path (the orbit). It is essentially in a state of perpetual freefall around the Earth. Energy is required for launching the satellite into orbit and for maneuvers to adjust or maintain the orbit, but not for the fundamental motion of orbiting once the orbit is established.

– Satellites orbit due to the balance between inertia and Earth’s gravity.
– Orbital motion itself is a form of freefall.
– No continuous energy input is needed solely to *stay* in orbit.

While continuous energy is not needed for orbiting, satellites do require energy for various operations, such as powering scientific instruments, communication systems, onboard computers, and making small adjustments to maintain the orbit (orbital maintenance burns using fuel). Solar panels convert sunlight into electrical energy for these purposes and for charging batteries. Retro-rockets are primarily used for de-orbiting or changing orbits, not for sustaining the orbital motion itself.

36. The first Indian Satellite, Aryabhatt, was launched in the year:

The first Indian Satellite, Aryabhatt, was launched in the year:

[amp_mcq option1=”1972″ option2=”1975″ option3=”1976″ option4=”1979″ correct=”option2″]

This question was previously asked in

UPSC NDA-2 – 2015

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India’s first satellite, Aryabhata, was launched on April 19, 1975.

Aryabhata was named after the ancient Indian mathematician and astronomer. It was launched by the Soviet Union from Kapustin Yar using a Kosmos-3M launch vehicle.

The satellite was built by the Indian Space Research Organisation (ISRO) to conduct experiments in X-ray astronomy, aeronomics, and solar physics. It marked India’s entry into the space age.

37. Which of the following statements with regard to the Square Kilometer

Which of the following statements with regard to the Square Kilometer Array (SKA) project is/are correct ?

1. SKA is a state of the art, mega science international facility to build the world’s biggest and most sensitive radio telescope for addressing a wide variety of cutting-edge science goals.
2. The Government of India has accorded its approval for India’s participation in the international mega science project.

Select the answer using the code given below :

[amp_mcq option1=”1 only” option2=”2 only” option3=”Both 1 and 2″ option4=”Neither 1 nor 2″ correct=”option3″]

This question was previously asked in

UPSC NDA-1 – 2024

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Both statements 1 and 2 are correct.

The Square Kilometer Array (SKA) is a massive international radio telescope project, and India is a full member contributing significantly to its development and operations.

1. The SKA project aims to build the world’s largest and most sensitive radio telescope, consisting of arrays of antennas spread across large areas in South Africa and Australia. It is designed to address fundamental questions in astrophysics, cosmology, and particle physics. Statement 1 accurately describes the nature and goals of the SKA project.
2. India is a founding member of the SKA Observatory (SKAO) Council, the intergovernmental organization responsible for constructing and operating the SKA telescopes. The Union Cabinet approved India’s financial participation in the SKAO project in June 2023, formalizing India’s continued significant role in the project. So, statement 2 is correct.

38. Which of the following is India’s first privately developed rocket lau

Which of the following is India’s first privately developed rocket launched by ISRO recently ?

[amp_mcq option1=”Skyroot” option2=”Prarambh” option3=”Bazoomq” option4=”Vikram-S” correct=”option4″]

This question was previously asked in

UPSC NDA-1 – 2023

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India’s first privately developed rocket launched by ISRO recently is named Vikram-S.

Vikram-S is the sub-orbital rocket developed by Skyroot Aerospace, a private Indian space startup. It was launched on November 18, 2022, as part of the ‘Prarambh’ (The Beginning) mission from ISRO’s launchpad at Sriharikota. This launch marked a significant milestone for India’s private space sector.

Skyroot Aerospace was the first Indian private company to sign a framework MoU with ISRO for access to its facilities and expertise, following space sector reforms enabling private participation. The ‘Vikram’ series of rockets are named as a tribute to the founder of India’s space program, Vikram Sarabhai.

39. Who among the following is appointed as the tenth Chairman of the Indi

Who among the following is appointed as the tenth Chairman of the Indian Space Research Organization (ISRO) recently?

[amp_mcq option1=”A. S. Kiran Kumar” option2=”K. Sivan” option3=”K. Radhakrishnan” option4=”S. Somanath” correct=”option4″]

This question was previously asked in

UPSC NDA-1 – 2022

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S. Somanath was appointed as the tenth Chairman of the Indian Space Research Organization (ISRO).

S. Somanath, a prominent rocket scientist, was appointed as the Chairman of ISRO and Secretary of the Department of Space in January 2022, succeeding K. Sivan. He is the 10th person to head the space agency since its formation.

Prior to his appointment as ISRO Chairman, S. Somanath was the Director of the Vikram Sarabhai Space Centre (VSSC) in Thiruvananthapuram. The first chairman of ISRO was Dr. Vikram Sarabhai.

40. Which one of the following statements with respect to Global Positioni

Which one of the following statements with respect to Global Positioning System (GPS) is not correct?

[amp_mcq option1=”It is based on network of satellites orbiting above the Earth.” option2=”It is based on the system of triangulation.” option3=”GPS receivers provide location in terms of latitude, longitude and altitude.” option4=”It provides information exclusively for military operations.” correct=”option4″]

This question was previously asked in

UPSC NDA-1 – 2022

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The correct answer is D) It provides information exclusively for military operations.

Let’s evaluate each statement:
A) It is based on network of satellites orbiting above the Earth. Correct. GPS relies on a constellation of dozens of satellites maintained by the United States.
B) It is based on the system of triangulation. Correct. GPS receivers calculate their position by determining the distance from multiple satellites. This process of determining location based on distance measurements from known points is often referred to as trilateration, which is similar in concept to triangulation (which uses angles).
C) GPS receivers provide location in terms of latitude, longitude and altitude. Correct. GPS provides a 3D position fix, including latitude, longitude, and height above a reference ellipsoid.
D) It provides information exclusively for military operations. Incorrect. While GPS was developed and is maintained by the U.S. military (Department of Defense), it has been available for civilian use globally since the 1980s and is used extensively for navigation, mapping, surveying, timing, etc., by both military and civilian users.

There are other global navigation satellite systems (GNSS) besides the U.S. GPS, such as Russia’s GLONASS, Europe’s Galileo, China’s BeiDou, and India’s NavIC. Modern receivers often use signals from multiple GNSS to improve accuracy and reliability.