Launch vehicles, satellites and applications

Prelims and Mains

Prelims asks what each mission was first to do, which is why this is worth holding as a list rather than as a history. Besides EOS-05 and Aditya-L1 above, these are the missions ISRO has recently flown and those it has approved or planned.

• Chandrayaan-3 made the first soft landing near the lunar south pole, on 23 August 2023.
• XPoSat is India's first X-ray polarimetry mission.
• SPADEX (Space Docking Experiment) made India the fourth country to dock two spacecraft in orbit.
• NISAR (NASA-ISRO Synthetic Aperture Radar), flown with the National Aeronautics and Space Administration (NASA) of the United States, is the first Earth observation satellite to carry radar in both the L and S bands.
• GSAT-7R (CMS-03) is a communications satellite for the Navy.
• The Venus Orbiter Mission is planned.
• Chandrayaan-4 is to bring a lunar sample back to Earth.
• LUPEX (Lunar Polar Exploration), also called Chandrayaan-5, is planned with the Japan Aerospace Exploration Agency (JAXA).

Prelims and Mains

The cycle an engine runs on decides how much of its propellant ends as thrust, and how hard the engine is to build. Full-flow staged combustion is the demanding end of that choice, which is why so few countries have flown it.

• A Bengaluru startup unveiled Everest, an 800 kN engine, making India the fourth country with full-flow staged combustion technology after Russia, the United States and China.
• It burns liquid oxygen and methane, a pair called methalox that leaves little soot.
• The cycle throttles precisely and suits reusable rockets.