Mars Orbiter readies to leave earth`s orbit

Bangalore: India`s Orbiter to Mars prepares to part with mother earth soon after Saturday midnight and begin its long journey to the distant red planet coasting through the cosmos for almost 10 months, a scientist said Friday.

"The Orbiter is steadily climbing towards its last apogee (farthest from earth) pass in the early hours (04:06 a.m.) Saturday and sling into the sun`s orbit at 01:12 a.m. Sunday after we fire its liquid engine at 12:49 a.m. for the trans-Mars injection," a senior space scientist said. After circling for the last time in its final geo orbit, the craft will escape earth`s gravitation to begin its 680-million km voyage Sunday for its rendezvous with the red planet in September 2014. "We are going to burn the liquid engine for nearly 23 minutes to impart an incremental velocity (speed) of 648 metres per second to the Orbiter, which will consume 198 kg fuel on board the spacecraft," said state-run Indian Space Research Organisation (ISRO) scientific secretary V. Koteshwar Rao. ISRO`s Telemetry, Tracking and Command Network (Istrac) in the city will give commands in advance for the slingshot to catapult the Orbiter into the heli-centric phase from the geo-centric phase to begin its inter-planetary space odyssey towards Mars. "We will make sure that we keep the Orbiter on-course by carrying mid-course corrections during its heliocentric phase," Rao said. India will become the first Asian country and fourth nation in the world to leap into the interplanetary space with its Rs.450-crore exploratory mission to Mars, about 400 million km from earth. The 1,337kg Orbiter was launched Nov 5 from Sriharikota spaceport off the Bay of Bengal, about 80 km north east of Chennai, aboard a 350-tonne rocket with five scientific instruments to detect methane in the Martian atmosphere, measure the thermal emission and capture images of the red planet from its orbit at a distance of 500 km. "The trans-injection exercise is a complex combination of navigation and propulsion technologies, governed by the gravity of sun and Mars," Rao noted. As the fourth planet from sun and behind earth, Mars is the second smallest celestial body in the solar system. Named after the Roman god of war, it is also known as red planet due to the presence of iron oxide in abundance, giving it a reddish appearance. Though earth and Mars have equal period of revolution around their axis, the red planet takes 24 hours and 37 minutes to complete a revolution. Earth takes around 365 days to orbit the sun and Mars 687 days. Once the Orbiter is placed in the Martian orbit, about 500 km from its surface, its five indigenous instruments onboard will commence their scientific observations.