Manoeuvre to raise orbit of Mars vehicle completed

This is the first major breakthrough of the Mission

The Indian Space Research Organisation (Isro) has successfully crossed its first major milestone by propelling the orbit of the Mars orbiter spacecraft. The orbit-raising manoeuvre was done at 1:17 am on Thursday, the birth anniversary of C V Raman, one of India’s most-famous scientists, by firing the spacecraft’s 440-Newton liquid engine for 416 seconds.

The command was given from the Spacecraft Control Centre (SCC) at Isro Telemetry, Tracking and Command Network at Peenya in Bangalore.

With this, the spacecraft's apogee (farthest point from Earth) has been raised to 28,825 km, while its perigee (nearest point to Earth) is at 252 km. On Wednesday, the spacecraft was parked on Earth’s orbit at 250 km by 23,500 km.

Isro officials said the second orbit-raising manoeuvre is set for Friday around the same time.

This is expected to raise the spacecraft’s apogee to 40,000 km. After six rounds of firing, the apogee will rise to 200,000 km. Each firing will make the spacecraft’s orbit bigger and the final one will be the largest. Thereafter, the spacecraft will go out of earth’s orbit.

The spacecraft has to rotate  around the Earth several times to attain the escape velocity (the lowest velocity a body must have to escape the gravitational pull of a planet) with minimum fuel consumption.

The firings are planned in a series of midnight manoeuvres, also known as Earth-bound manoeuvres.

This is done by firing the spacecraft’s engine in a direction tangential to the Earth, while the spacecraft is at its closest orbital position to the globe.

The injections to increase its elliptical distance around the Earth have been scheduled on November 7, 8, 9, 11 and 16. Thereafter, MOM will be mainly under the influence of Sun's gravity and it sets foot on its elliptical journey around the Sun. This elliptical orbit is designed for MOM to rendezvous with Mars in September 2014, said ISRO officials.

“Ever day, and everything, is crucial in this mission,” said Isro's spokesperson. He added that all systems onboard the spacecraft are functioning normally.

Further orbit-raising manoeuvres using the 440 newton liquid engine are planned in the coming few days following which the spacecraft will be put on the Mars transfer trajectory on December 1. This will enable the orbiter to travel to the vicinity of Mars in September 2014 after a 300-day journey in deep space. At that time, the 440 newton liquid engine will be fired again to slow down the spacecraft to enable it to be captured by Martian gravity into the orbit around it, the ISRO spokesperson noted.

It’s over to ISTRAC now

The action has now shifted to ISTRAC in Bangalore. It is a collection of many state-of-the-art ground-based stations. It has 18-metre and 32-metre antennae of the Indian Deep Space Network, Indian Space Science Data Centre and the Mission Control Centre.

Through the mission, ISTRAC will monitor, command, navigate and control the spacecraft. The orbit-raising manoeuvres between November 7 and December 1 are being done from ISTRAC.

The crucial moment will be on December 1 at 12.42 am, when scientists will give the trans-Martin injection, following which the spacecraft will start its voyage of 300 days to Mars, under the influence of the sun. The orbiter is expected to reach the Mars orbit on September 24.