New Delhi, Nov 13 (): ISRO scientists have raised the apogee (farthest point from Earth) of India’s first Mars orbiter spacecraft to more than one lakh km on Tuesday; now the spacecraft is back into action after a day of concern during the fourth orbit raising manoeuvre.
On Monday, a stop in the flow of the liquid engine had reduced down the orbit-raising operation, as an apogee of 71,623 km could only be achieved as against the desired orbit of 1 lakh km. This was corrected with Tuesday’s exercise.
This means that the spacecraft is all ready to leave the orbit of Earth. This exercise called the trans-Martian injection, is planned for December 1.
A day earlier, ISRO scientists had told that it would prove to be a setback for the entire mission if the engine refused to start up. But, the problem was not major. It was caused when the solenoid valve, which controls the flow of liquid propellant to the engine, shut out when the Spacecraft Command Centre at Peenya in Bangalore was testing a back-up sequence.
However, the fourth orbit raising manoeuvre had not been completely derailed by the closing off the solenoid valve, as the Mars Orbiter had autonomously started the smaller 22 Newton Attitude Thrusters. Then, the apogee had been elevated from 71,623 km to 78,276 km. The target had been to increase the apogee to 100,000 km.
ISRO then made slight adjustments to the mission and used the supplementary orbit raising manoeuvre to 118,642 km in the operation. The fifth orbit raising manoeuvre is scheduled to be performed in the wee hours of November 16, and ISRO will attempt to raise the apogee to 200,000 km.
The Mars orbiter will continue to revolve around Earth till November 30, and then the aircraft will begin its journey to Mars. On December 1, the craft will be powered out of Earth’s orbit on its way to Mars.
The Indian spacecraft will travel for almost 300 days, cover 400 million kilometres and finally reach Mars on September 24, 2014.
The 450-crore “Mangalyaan” mission has already made headlines as the cheapest mission to Mars. It should be noted that majority of Mars missions, including China’s Yinghuo-1 mission and Japan’s Nozomi mission have failed.