The Indian Space Research Organisation (ISRO) on Monday reported that a key engine on board its Mars Orbiter Spacecraft, which is currently within striking distance of the Red Planet, had been successfully test-fired.
The test-firing of the main liquid engine of the spacecraft sets the stage for its insertion into the orbit of Mars on September 24. The engine, known as the Liquid Apogee Motor, needs to fire for 24 minutes on Wednesday for ISRO to successfully dock the spacecraft in an orbit around Mars at a nearest distance of 423 km.
The engine had been lying idle since December 1, when it was fired for 21 minutes, sending the spacecraft on the final leg of its 666 million km journey to Mars.
Monday’s exercise was intended as a test of the functioning of the dormant engine as well as a new fuel supply route in the engine. It also involved a small course correction measure to take the spacecraft closer to Mars.
The firing of the engine on Monday for around four seconds was intended to slow down the spacecraft by around 2.14 metres per second and set it up at a distance of 515 km from Mars ahead of the final capture into the orbit on September 24 at 7.30 am.
On Wednesday, the engine will fire again for about 24 minutes, imparting a deceleration force of 1098.7 metres per second to enable the spacecraft to slip into an orbit with a nearest distance of 423 km to the Red Planet and a farthest distance of 80,000 km. The manoeuvre will consume 249.5 kg of the 280 kg fuel on board the spacecraft.
Failure of the engine to fire on Monday would have forced ISRO to adopt plan B, wherein eight small thrusters on the spacecraft would have been fired to enable it to dock into the orbit of Mars. However, it would not have been as close to the planet, and would have consumed the entire 280 kg of fuel.
“If the trajectory correction manoeuvre is not carried out, the spacecraft would arrive at a distance of 723 km from the surface of Mars ahead of the September 24 manoeuvre. With the correction, it will reach at a trajectory of 513 km,” ISRO scientific secretary V Koteswara Rao said.
ISRO’s Rs 450 crore Mars mission, launched on November 5, 2013 on board the PSLV-C25 rocket, is one of the cheapest voyages undertaken by any space faring nation. If successful, it will put ISRO among a league of three other agencies that have achieved success on missions to Mars.
The spacecraft is scheduled to enter the orbit of Mars exactly 48 hours after NASA’s 16th successful Mars mission with its Maven spacecraft on Monday.
Prime Minister Narendra Modi, who will be in Bangalore on Wednesday, is scheduled to visit ISRO’s mission operation centre in Peenya to congratulate scientists if the mission goes according to plan. Modi, who witnessed the successful launch of five foreign satellites on the PSLV-C23 rocket from the Satish Dhawan space centre at Sriharikota on June 30, had said at the time that he was waiting eagerly for the successful outcome of India’s Mars mission.
Indian space scientists are banking on a successful Mars mission to push ahead more ambitious programmes, like a maiden manned space flight and a manned moon mission. The ongoing Mars mission is intended to study methane on the Red Planet and look for possible signs of life there.