Mangalyaan orbit-raising a success

A supplementary orbit-raising maneuver to compensate for an engine under-performance Monday the third orbit-raising saw the Mars orbiter spacecraft placed at a height of 1,18,642 km on Tuesday. The “fourth supplementary orbit-raising manoeuvre of Mars Orbiter Spacecraft, starting at 5.03 am on November 12, with a (engine) burn time of 303.8 seconds has been successfully completed. The observed change in apogee is from 78,276 km to 1,18,642 km,” the Indian Space Research Organisation (Isro) said in a statement. Isro had suffered a temporary setback on Monday when a plan to raise the height of the spacecraft from 71,623 km to 1,00,000 km failed with the liquid engine on board shut down during a function test. The Monday maneuver had raised the spacecraft to a height of 78,276 km from 71,263 km instead of the intended 1 lakh km, necessitating the supplementary fourth orbit-raising maneuver. The orbit is raised by firing the 440 Newton liquid engine of the spacecraft from the spacecraft control centre at the Isro telemetry, tracking and command network at Peenya in Bangalore. In the first move, the engine was fired for 412 seconds, for 570.6 seconds in the second and for 707 seconds in the third. Isro hopes to raise the orbit to a height of 2 lakh km by November 30 to generate the velocity to slingshot the spacecraft towards Mars on December 1. The agency had initially hoped to carry out six maneuvers to raise the spacecraft orbit to 2 lakh km.