Science and Technology (Part-I)

Total Questions: 50

1. With reference to Indian satellites and their launchers, consider the following statements: [2002]

1. All the INSAT series of satellites were launched abroad.

2. PSLVs were used to launch IRS-series of satellites.

3. India used the indigenously built cryogenic engines for the first time for powering the third stage of GSLV.

4. GSAT, launched in the year 2001, has payloads to demonstrate digital broadcasts and internet services.

Which of these statements are correct?

Correct Answer: (a) 1, 2, 3 and 4
Solution:PSLV is designed mainly to deliver the "earth-observation" or "remote-sensing" satellites with lift-off mass of up to about 1750 Kg to Sun-Synchronous circular polar orbits of 600-900 Km altitude. It is also used to launch the satellites of lower lift-off mass of up to about 1400 Kg to the elliptical Geosynchronous Transfer Orbit (GTO).

The GSLV is designed mainly to deliver the communication-satellites to the highly elliptical Geosynchronous Transfer Orbit (GTO). The satellite in GTO is further raised to its final destination, viz., Geo-synchronous Earth orbit (GEO) of about 3.6000 km altitude (and zero degree inclination on equatorial plane) by firing its in-built on-board engines.

Due to their geo-synchronous nature, the satellites in these orbits appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth. Therefore, statement 1 is correct and statement 2 is incorrect.

GSLV-Mk III is a three-stage vehicle with two solid motor strapons (S200), a liquid propellant core stage (L110) and a cryogenic stage (C-25). Statement 3 is incorrect.

2. Assertion (A): Artificial satellites are always launched from the earth in the eastward direction. [2002]

Reason (R): The earth rotates from west to east and so the satellite attains the escape velocity.

Correct Answer: (c) A is true but R is false
Solution:The surface velocity of rotation varies from point to point on the Earth. It is about 1600 km per hour or about 460 meters in a second near the equator. The velocity gradually reduces as we move to the poles and it is practically zero there. A satellite launched from the sites near the equator towards the east direction will get an initial boost equal to the velocity of Earth surface. This is similar to an athlete circling round and round before throwing a discus or a shot put. The initial boost helps in cutting down the cost of rockets used to launch the satellites. This is the major reason for launching satellites in the east ward direction. But this benefit can be taken only for such satellites which are placed in geo-stationary orbit or which circle the Earth parallel to the equator.

3. Consider the following statements: [2003]

1. India launched its first full-fledged meteorological satellite (METSAT) in September, 2002

2. For the first time, the space vehicle PSLV C-4 carried a payload of more than 1000 kg into a geosynchronous orbit Which of these statement is/are correct?

Correct Answer: (c) Both 1 and 2
Solution:METSAT was the first Indian (ISRO), Meteorological geostationary satellite designed to simultaneously obtain atmospheric cloud cover, water vapour and temperature data. PSLV-C4 carried a payload of 1060 kg in to a geosynchronous orbit.
Types of Weather Satellites
• Geostationary Satellites (GEO): Orbit at an altitude of approximately 35,786 kilometers above the equator, allowing them to remain stationary relative to a specific point on Earth. They provide continuous monitoring of a specific region, such as a continent or an ocean.
• Polar Orbiting Satellites (PO): Orbit the Earth from pole to pole, providing global coverage. They operate at lower altitudes (typically 800–1,200 kilometers) and are crucial for collecting detailed information about the atmosphere, including temperature, humidity, and cloud cover.

4. NASA's Deep Impact space mission was employed to take detailed pictures of which comet nucleus? [2007]

Correct Answer: (d) Tempel 1
Solution:

Deep Impact was a NASA space probe launched from Cape Canaveral Air Force Station on January 12, 2005. It was designed to study the interior composition of the comet Temple 1.
About Comet
• Comets are large objects made of dust and ice that orbit the Sun.
• Best known for their long, streaming tails, these ancient objects are leftovers from the formation of the solar system 4.6 billion years ago.
• Comets are mostly found way out in the solar system.
• Some exist in a wide disk beyond the orbit of Neptune called the Kuiper Belt.
• We call these short-period comets. They take less than 200 years to orbit the Sun.
• Other comets live in the Oort Cloud, the sphere-shaped, outer edge of the solar system that is about 50 times farther away from the Sun than the Kuiper Belt.
• These are called long-period comets because they take much longer to orbit the Sun.

5. Which one of the following pairs is not correctly matched? [2007]

Correct Answer: (d) Atlantis: Space station
Solution:Atlantis was a Space Shuttle orbiter of National Aeronautics and Space Administration (NASA).
NASA (which stands for the National Aeronautics and Space Administration) is the main U.S. agency for space exploration. It was started back in 1958, partly because the Soviet Union had just launched Sputnik, the first satellite. NASA is a world leader in exploring space, doing everything from building satellites and sending people into space to exploring other planets and carrying out advanced science. What NASA does helps create new technologies we can all use and encourages countries to work together peacefully in space.

6. Selene-1, the lunar orbiter mission belongs to which one of the followings? [2007]

Correct Answer: (c) Japan
Solution:Mitsubishi Heavy Industries, Ltd. and the Japan Aerospace Exploration Agency (JAXA) launched the Lunar Orbit Explorer "KAGUYA" (SELENE) at on September 14, 2007, from the Tanegashima Space Center. The major objectives of the mission are to understand the Moon's origin and evolution and to observe the Moon in various ways in order to utilize it in the future.

7. ISRO successfully conducted a rocket test using cryogenic engines in the year 2007. Where is the teststand used for the purpose, located? [2008]

Correct Answer: (c) Mahendragiri
Solution:It is located in Mahendragiri, Tamil Nadu.

• ISRO was set up initially in 1962 as the Indian National Committee for Space Research (INCOSPAR), based on the suggestions of Dr Vikram Sarabhai.
• In 1969, INCOSPAR was remodeled as ISRO to work within the Department of Atomic Energy (DAE). In 1972, the Government of India institutionalized space research activities in India by setting up the Space Commission and the DoS.
• ISRO is India’s national space agency and acts as a primary research and development arm of the Department of Space (DoS).
• Primary Role: ISRO has the primary role of performing tasks related to space-based operations, space exploration, international space cooperation, and the development of related technologies.

Major Features of ISRO
• Full Launch Capabilities: ISRO is one of the six government space agencies in the world that possesses full launch capabilities.
• Extra-terrestrial Missions: ISRO possesses the capability to launch extraterrestrial missions.
• Operate Artificial Satellites: ISRO has developed the ability to launch and operate a large number of artificial satellites.
• Soft-landing Capability: Through the Chandrayaan-3 mission, ISRO has shown its ability to make soft-landing.

8. Which one of the following is a spacecraft? [2008]

Correct Answer: (b) Cassini
Solution:

Cassini is an unmanned spacecraft sent to the planet Saturn.
Key unmanned missions
• Chandrayaan-1: India’s first unmanned lunar mission, which successfully confirmed the existence of water on the Moon.
• Mars Orbiter Mission (MOM): A low-cost, successful mission that was India’s first interplanetary mission, demonstrating significant technological capabilities.
• Gaganyaan Mission: The programme includes two unmanned precursor flights to test safety and technology before the manned mission. The first unmanned mission, originally planned for 2020, was delayed due to the pandemic. The missions will test the safe re-entry and orientation of the crew module, which will not initially have the life support system.
• Aditya-L1: An upcoming mission to study the Sun.
• NISAR: A joint NASA-ISRO satellite for Earth observation.

9. What is the purpose of the US Space Agency's Themis Mission, which was recently in the news? [2008]

Correct Answer: (c) To study the colourful of display of high latitude skies
Solution:The Themis mission, comprising five identical probes, aims to gain new insights into the colorful displays in high-latitude skies.
• In 2007, THEMIS “found evidence of magnetic ropes connecting Earth’s upper atmosphere directly to the Sun”, reconfirming the theory of solar-terrestrial electrical interaction (via “Birkeland currents” or “field-aligned currents”) proposed by Kristian Birkeland circa 1908. NASA also likened the interaction to a “30 kiloVolt battery in space”, noting the “flux rope pumps 650,000 ampere current into the Arctic”.
• On 26 February 2008, THEMIS probes were able to determine, for the first time, the triggering event for the onset of magnetospheric substorms. Two of the five probes, positioned approximately one third the distance to the Moon, measured events suggesting a magnetic reconnection event 96 seconds prior to Auroral intensification. Vassilis Angelopoulos of the University of California, Los Angeles, who is the principal investigator for the THEMIS mission, claimed, “Our data show clearly and for the first time that magnetic reconnection is the trigger”.

10. In the context of space technology, what is "Bhuvan", recently in the news? [2010]

Correct Answer: (c) A geoportal of ISRO with 3 D imaging capabilities of India.
Solution:Bhuvan, is a software application which allows users to explore a 2D/3D representation of the surface of the Earth. ISRO launched the beta version of its web-based GIS tool, Bhuvan, on August 12, 2009.

Bhuvan offers detailed imagery of Indian locations compared to other Virtual Globe Software, with spatial resolutions ranging up to 1 metre.