Mars spacecraft crosses sphere of influence of Earth

India’s Mars Orbiter Mission notched up another achievement at 1.14 a.m. on Wednesday when the spacecraft to the Red Planet crossed the sphere of influence (SOI) of the Earth, traversing beyond 9.25 lakh km. The SOI of the Earth extends to about 9.25 lakh km from it. The spacecraft is now into the sun-centric orbit proper.

Deviprasad Karnik, spokesperson, Indian Space Research Organisation, said, “This is the first time that any Indian spacecraft has crossed this distance. It has entered the interplanetary regime now. It has entered the sun-centric orbit.”

The spacecraft crossed the SOI of the Earth around 1.14 a.m. Wednesday, exactly 72 hours after it was slung out of its Earth-bound orbit on Sunday.

India’s Mars spacecraft will now coast around the sun for the next 300 days before it has its rendezvous with Mars on September 24, 2014.

Around 00.49 hours on Sunday, ISRO fired the spacecraft’s propulsion system for 23 minutes. At the end of the 23 minutes of ignition of this propulsion system, called 440 Newton engine, the Mars spacecraft was catapulted out of its Earth-bound orbit towards the sun-centric phase.

With the orbiter now sailing in the inter-planetary regime, ISRO will correct the spacecraft’s trajectory three or four times before firing its propulsion system on September 24, 2014 to insert the spacecraft into the Martian orbit with a peri-apsis of 376 km and an apo-apsis of 80,000 km.