Space and Space Technology: UPSC Previous Year Questions (Science and Technology)

Explanation

Option (d) is correct: Tempel 1 was the target of NASA’s Deep Impact mission launched in 2005. The mission involved sending an impactor spacecraft to collide with the comet’s nucleus, creating a crater and allowing scientists to study the composition and structure of the comet’s interior. The mission provided valuable data about the formation of the solar system.

Option (a), (b) and (c) are incorrect:

Halley’s Comet is one of the most famous comets which is known for its periodic appearance every 76 years. It was last observed in detail by the European Space Agency’s Giotto mission in 1986. Hale-Bopp was a bright comet that became visible to the naked eye in 1997. It was extensively studied by ground-based telescopes and space observatories. Comet Hyakutake was another bright comet that passed close to Earth in 1996. It was studied by ground-based telescopes and space observatories but was not the target of the Deep Impact mission.

Explanation

Pair (a) is correctly matched: COBE (Cosmic Background Explorer) was a satellite launched by NASA to study the cosmic microwave background radiation and provide evidence supporting the Big Bang theory. Pair (b) is correctly matched: The FLAG Alcatel-Lucent Optical Network (FALCON) submarine cable system is a 11,859 km undersea cable connecting multiple countries, including India, Sri Lanka, and Egypt, facilitating international telecommunications. Pair (c) is correctly matched: Discovery was a part of NASA’s Space Shuttle program and completed numerous missions. It conducted various missions, including deploying satellites, servicing the Hubble Space Telescope, and assembling the International Space Station (ISS). Pair (d) is incorrectly matched: Space Shuttle Atlantis was one of NASA’s reusable spacecraft used for human spaceflight missions. It is not a space station but a space shuttle that transported astronauts and cargo to space.

Explanation

NASA’s THEMIS mission (launched in 2007) investigates the origin and mechanisms of auroras, the colorful lights in high-latitude skies caused by interactions between Earth’s magnetosphere and solar wind. The mission studies substorms--sudden energy releases in the magnetosphere--and processes like magnetic reconnection and plasma waves. that magnetotail reconnection triggers substorms, improving understanding of space weather and its impacts on satellites, communication systems. The mission contributes to heliophysics by exploring Earth’s magnetosphere dynamics. Its primary goal was to study auroras and their connection to energy releases in the magnetosphere.

Explanation

METSAT (renamed as Kalpana - 1) was the first in the series of exclusive meteorological satellites built by ISRO.

Statement 1 is correct: India successfully launched its first full-fledged meteorological satellite, METSAT using the PSLV-C4 rocket. It was India’s first dedicated meteorological satellite, designed to monitor weather conditions and cyclone development in the Indian Ocean region.

Statement 2 is correct: PSLV-C4 carried METSAT (1,060 kg) into a geosynchronous transfer orbit (GTO), marking the first time PSLV carried a payload exceeding 1000 kg into GTO. This demonstrated ISRO’s ability to deploy heavier payloads into higher orbits, advancing India’s space technology capabilities.

Explanation

INSAT or the Indian National Satellite System is a series of multipurpose Geostationary satellites launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue needs of India.

Statement 1 is correct: The INSAT-series of satellites were launched from foreign stations like Kourou in French Guiana or Kennedy Space Center in the USA.

Statement 2 is correct: The PSLV (Polar Satellite Launch Vehicle) was used to launch many of the IRS (Indian Remote Sensing) satellites, which are used for Earth observation.

Statement 3 is correct: India’s first cryogenic engine was used for the third stage of the GSLV (Geosynchronous Satellite Launch Vehicle) for the first time in the launch of GSLV-D3 in 2010.

Statement 4 is correct: GSAT-1, India’s first geostationary communication satellite, was launched in 2001, and its payloads were designed to provide digital broadcast and communication services, including internet services.

Explanation

A satellite is an object in space that orbits or circles around a bigger object. There are two kinds of satellites: natural (such as the moon orbiting the Earth) or artificial (such as the International Space Station orbiting the Earth). Almost every planet having at least one moon. Assertion (A) is true: Satellites are launched in the eastward direction to take advantage of the Earth’s rotational velocity, which gives the rocket an initial boost in speed. This helps the rocket reach the required escape velocity more efficiently. Reason (R) is false: While the Earth’s rotation does provide a velocity boost but it does not directly help the satellite attain escape velocity (the speed needed to break free from Earth’s gravity, approximately 11.2 km/s). Instead, the Earth’s rotation helps the satellite achieve orbital velocity (the speed needed to stay in orbit, approximately 7.8 km/s for low Earth orbit).