RAS question
Mars Orbiter Mission (Mangalyaan) made India the first Asian country to reach Mars orbit. Its primary propulsion is:
Correct answer: (A) 440N Liquid Apogee Motor.
Mars Orbiter Mission used a 440N Liquid Apogee Motor as its primary propulsion system for trajectory correction and Mars orbit insertion.
Explanation
Mars Orbiter Mission's primary propulsion was the 440N Liquid Apogee Motor, or LAM. ISRO's official MOM booklet describes LAM as the spacecraft's main liquid rocket engine: PSLV-C25 placed the spacecraft only in an Earth orbit, after which LAM had to take it towards Mars and help it circle the planet. The same booklet says the main liquid rocket engine was fired during the November 2013 orbit-raising phase, and that LAM fired again on September 24, 2014, with eight thrusters, to slow the spacecraft enough for Mars gravity to capture it in orbit. MOM therefore used the 440N LAM for trajectory correction and Mars orbit insertion, on a mission launched by PSLV-C25 at an estimated cost of Rupees 450 crore.
Why the other options are wrong
- (B) Ion propulsion is wrong because MOM did not use ion propulsion, while ISRO identifies LAM as the spacecraft's main liquid rocket engine.
- (C) Nuclear thermal propulsion is wrong because MOM did not use nuclear propulsion, and ISRO's official MOM booklet describes a chemical liquid-engine system using LAM and thrusters.
- (D) A solid rocket motor is wrong because solid motors belonged to the PSLV launch vehicle stages, while the spacecraft's own Mars-transfer and orbit-insertion work was assigned to LAM.
Concept
This tests the space-technology part of Science and Technology, especially matching Indian missions with their propulsion and mission-critical systems. It recurs in RAS because ISRO missions are asked not only as current affairs but also as applied technology facts.