The Indian Space Research Organisation (Isro) has geared itself for the fifth orbit raising operation of the Mangalyaan at 2:27 am on Saturday, the final one in a series of earth-bound manoeuvres before being finally ejected out of the earth’s sphere of influence on December 1.
The apogee(farthest point from earth) after the fifth firing will be increased from 1,18,600 km to 1,92,874 km. The velocity will be increased to 101m/sec.
This will be the final earth bound manoeuvre before the crucial Trans-Mars injection on December 1 for the spacecraft to move out of the sphere of influence of earth towards Mars.
There was a glitch in the fourth orbit raising operation following which a supplementary operation had to be done to raise the apogee.
During the orbit-raising operations conducted since November 7, Isro has been testing and exercising the autonomy functions progressively that are essential for Trans-Mars Injection (TMI) and Mars Orbit Insertion. The spacecraft has to take several rounds around earth to gradually increase its velocity to attain escape velocity with minimum fuel consumption.