In final lap, ISRO's Mars spacecraft to burn 240 kgs-fuel to slowdown, enter Martian orbit

Written by Avinash Nair | Ahmedabad | Updated: Aug 3 2014, 00:11am hrs
Mars missionOnce placed in the orbit, the spacecraft is scheduled to scan and study the atmosphere of red-planet for a period of six months. Reuters
In it's final lap, India's Mars Orbiter spacecraft will burn a bulk of the 290 kilograms of fuel left in its fuel-tanks, when it slows down and performs a crucial manoeuvre to enter the Martian orbit next month, ISRO officials said here today. Once placed in the orbit, the spacecraft is scheduled to scan and study the atmosphere of red-planet for a period of six months.

"It is currently about 163 million kilometers away from Mars. It is travelling at a speed of 1.2 million kilometers per day. It is on schedule and on target. Originally we were planning to have a corrective manoeuvre on August 19. But in the current situation, we don't think it is necessary. So the next (trajectory) correction is scheduled for September 14 and on September 24, the orbiter is supposed to reach Mars and perform the manoeuvre to orbit the red planet," said A S Kiran Kumar, director Space Applications Centre, Indian Space Research Organisation (ISRO) while explaining the Mars Orbiter Mission (MOM) spacecraft will undergo a final trajectory correction on September 14, before it goes ahead and performs this crucial manoeuvre ten days later to enter the Martian orbit.

"We have 290 kilograms of fuel left, and we will require about 240 kilograms for the manoeuvre to enter the Mars orbit. The process will involve reducing the velocity of the spacecraft and allowing it to get captured by Mars' (gravity)," Kiran Kumar told The Indian Express at the sidelines of a conference on "Intellectual Property Rights in Electronics, IT and ICT organised by Confederation of Indian Industry (CII) and Government of Gujarat here on Saturday.

The veteran scientist who is a crucial part of the MOM said the orbiter will be slowed down by reducing its velocity by one kilometer per second roughly from it's current velocity.

"The liquid apogee motors that were used to push the spacecraft out of the earth's orbit, will be reoriented and fired, thus slowing down the spacecraft. It is a one time opportunity and has to be done precisely," Kiran Kumar said about the 440 Newton apogee motor on board the MOM spacecraft that will have to be restarted after 300 days since it was last fired during the Trans-Mars Injection phase.

ISRO officials point out that there is "no scope of error" during this nail-biting manoeuvre that will help tag India as the first Asian country to successfully reach Mars in it's maiden attempt.

"There is no scope for error," he said adding that all the commands will be fed in to the spacecraft three days in advance (before the manoeuvre on September 24) and the manoeuvre is expected to happen using the autonomous features of the spacecraft at 7:30 am on September 24. "In the previous activities, all the mechanisms and functionalities have got tested for this crucial manoeuvre," he added.

The MOM spacecraft that was launched on November 5, 2013, initially carried over 850 kilograms of fuel.