ISRO readies to thrust spacecraft out of Earth orbit on December 1

The first Indian Mars mission began its last orbit around the Earth on Wednesday morning, even as its controllers prepared for the big night three days away.

On the night of November 30-December 1, the spacecraft will be finally thrust away from the Earth, and all the way towards the Red Planet, after gathering a total escape speed of around 11.4 kms a second.

Indian Space Research Organisation’s Scientific Secretary V. Koteswara Rao told a pre-event briefing at the control centre at the Telemetry, Tracking and Command Network (ISTRAC) on Wednesday, “We are planning for the Mars spacecraft to depart the Earth in the early hours of December 1.”

‘Second big challenge’

Dozens of controllers at the Mission Operations Complex at ISTRAC were getting set for what the space agency’s chairman, K. Radhakrishnan, earlier termed ‘the second big challenge in the Mars mission’: the day when they must precisely increase the spacecraft’s velocity and slingshot it exactly towards Mars.

Saturday’s trans-Mars insertion (TMI) is set for 12.49 am. The spacecraft has been orbiting the Earth once in almost four days or 91.3 hours, since November 16.

About the TMI, Mr. Rao said, “On that day we must burn the liquid engine for roughly 23 minutes, which will impart to it an incremental velocity of 648 metres per second. Then begins a journey of 680 million km over 300 days.”

Once it nears Mars, we will have another major operation in September 2014 to make it orbit the planet, he said.

In six orbit-raising operations from November 7 to November 16, the spacecraft has gradually been given its present velocity of 873 metres a second and it reached an apogee (farthest point) of 1.92 lakh km.

Once it moves beyond 2 lakh km, ISTRAC’s Indian Deep Space Network at Byalalu would come into the picture with its two large antennas which can track huge interplanetary missions.

The spacecraft carrying five instruments to study Mars was launched on November 5 from Sriharikota.