Bengaluru: At 2:45 pm on Monday, a stack of numbers flickered across an array of computers at the Spacecraft Control Centre at ISRO’s Telemetry, Tracking and Command Network (ISTRAC) facility in Bengaluru, setting off a loud cheer among space scientists. These numbers signalled the success of a critical test of the motor onboard Mangalyaan ahead of its entry into an orbit around Mars on September 24.
India's maiden Mars mission was on course to reach the Red Planet's orbit on Wednesday. With precision, the motor was switched on for about four seconds at 2:30 pm after a gap of nine months and 20 days, reducing the speed of the Orbiter by 2.18 meters per second, only hours after it entered the Martian neighbourhood or about 5.8 lakh km away from the planet.
About half a kg of fuel was used to test the motor and decrease the probe's speed as space scientists chose to save the rest for the 24.23 minute operation when they would guide it into an orbit about 423 km from the planet, and 215 million km from the earth.
Reaching the Martian neighbourhood itself is a feat for an Asian nation, but these self-effacing space scientists chose not even to bite into a sweet to celebrate the occasion. “It was just a round of applause and then we got into discussions with engineers who will monitor the Orbiter during the next 24 hours,” a top ISRO scientist told Deccan Chronicle.
With Monday's test of the motor and correction of the Orbiter's trajectory, space scientists are more confident that it would arrive at the precise orbit on September 24, says Dr. S. K. Shivakumar, Director, ISRO's Satellite Centre (ISAC), Bengaluru, where the orbiter was assembled. "Today's operation can be described as the semifinal. The motor functioned as expected and with clock-work precision. Signals from the orbiter were first received at ground stations in Canberra and Byalalu (Indian Deep Space Network), and then transmitted to ISTRAC to confirm that the test was successful," Dr Shivakumar added Shorn of the technical jargon on the 440 Newton Liquid Apogee Motor (LAM), Monday's manoeuver generated as much force as a man weighing 44 kg on a bicycle would, so that the speed would constantly increase at one meter every second because of lack of gravity or friction in outer space. All five instruments onboard the 475 kg orbiter have been tested en route, and will be switched on only after entering the orbit on Wednesday.
Co-incidentally, NASA's MAVEN (Mars Atmosphere and Volatile Evolution) probe entered the Martian orbit early on Monday after a 10-month voyage from the earth to explore the Red Planet's upper atmosphere, its history and climate for human expeditions in future. With a top scientist of NASA speaking about the possibility of a joint working group on Mars, scientists of both these space agencies are likely to match data beamed by Mangalyaan, MAVEN and even the rover "Curiosity" to solve several mysteries about the Red Planet and origin of the universe.
