CHENNAI: Sleepless Indian space scientists on Sunday began the process of ‘waking up’ the engine of the Mars Orbiter Mission (MOM) spacecraft for a four-second test on September 22.Three days later, it will be put to its ultimate test — firing for 24 minutes to slow down the MOM and inject it into the Martial orbit. Should they pull it off, India will be the first country to do so on debut.The US, Russia and the European Space Agency had got it right after repeated attempts.MOM, hurtling at a speed of 82,000kmph, has been idling for about 300 days since it left the Earth’s influence on November 30, 2013.“We have to see if the engine is in shape, hence the test,” said Isro chairman K Radhakrishnan. “It will also serve as a trajectory correction which will take MOM to a 515km arrival spot from Mars.”On Sunday, scientists at Isro Telemetry Tracking and Command Network in Bangalore sent a bundle of commands to test-fire the liquid apogee motor (LAM) engine for four seconds.MOM project director S Arunan said the test-firing would take the spacecraft, moving at a speed of about 22km per second, away from the trajectory by more than 100km, but this would be factored in to the final Martian orbital injection on September 24.Isro chairman K RadhakrishnanMOM would be reaching the Martian orbit two days after the US orbiter MAVEN. With the ingenuous sling-shot approach, India has been able to send the orbiter to Mars at Rs450 crore, which is 10 times less than the cost of the Nasa mission. Prime Minister Narendra Modi had said India could launch this mission at the cost of the Hollywood film ‘Gravity’.Once in orbit around the red planet , MOM will study its atmosphere, mineralogy and morphology. More than the results of the scientific studies, the mission will serve as a starting point for India’s interplanetary exploration.