‘First orbit manoeuvre is special’

Wednesday was a “travel day” back home for ISRO Chairman and several key officials from various centres who had gathered at Sriharikota to see the Mars orbiter off.

In Bangalore, the theatre of post-launch activity till the end of the Mars mission, about 30 scientists from across ISRO centres were in position at the telemetry and tracking unit, ISTRAC.

Over the next 24 days they will watch over and coaxing their newest baby through November, first to travel loop by loop around Earth and later towards Mars. ISTRAC (ISRO Telemetry, Tracking & Command Network) Director B.S.Chandrashekar, told The Hindu, “Each orbit manoeuvre of any spacecraft is special to us, especially the first one and we do it all with utmost care and as per a plan.”

He said, “This mission has special significance. We do not have the fuel margin and have to be careful [not to waste fuel while firing the motor.]” The engine burns consume fuel on the spacecraft and it has to be conserved through its journey to Mars and beyond.

During what are called orbit-raising manoeuvres, the scientists will gradually push out the elliptical orbit of the spacecraft at its farther end from Earth (or apogee’).

The post-launch mission operations are supervised by V.Kesava Raju of the ISRO Satellite Centre.

The ISTRAC normally handles the low-orbiting remote sensing satellites that circle at 600-odd km from ground. It also tracked and commanded Chandrayaan-1 of 2008-09 all the way to Moon, four lakh km away.

Handling an elliptical orbit of the Mars orbiter would be similar to ISTRAC’s regular operations, although remote sensing satellites need far less corrections than now, Mr. Chandrashekhar said.

All along, scientists from various ISRO centres would be watching the performance of the respective sub-systems that they built for the spacecraft. Mr. Chandrashekar said the team would be larger during the initial burns.