By Venkatachari Jagannathan
Bangalore/Chennai: Cruising at 32km per second, the Indian spacecraft to Mars is now in the sun’s orbit on its way towards the red planet after leaving earth’s gravity early Sunday, making India the first Asian country and fourth in the world to leap into interplanetary space.
“The spacecraft (Orbiter) is on course to encounter Mars, coasting at 32km per second to traverse the 680-million km sun’s orbit in 298 days and reach the red planet Sept 24, 2014,” a senior space agency official said.
India’s Rs.450-crore exploratory mission to Mars, about 400 million km from earth, makes it the part of a elite grouping including Russia, US and the European Space Agency (ESA) which have undertaken such missions.
“The Orbiter is healthy and its subsystems are normal. It will leave the earth’s sphere of influence Dec 4 to free from its gravitational pull, which extends up to 918,347 km in space,” state-run Indian Space Research Organisation (ISRO) director Deviprasad Karnik told IANS.
The Orbiter was flung into outer space at 1.11 a.m. after its engine was fired at 12.49 a.m. for 22 minutes for the crucial trans-Mars injection at a velocity (speed) of 648 metres per second.
“The trans-Mars injection operation was successful. Everything went off well and all systems onboard the spacecraft are working well,” ISRO chairman K. Radhakrishnan told IANS on phone.
Scientists at the space agency’s Telemetry, Tracking and Command Network (Istrac), handling the Orbiter geo-centric phase, however, had some anxious moments as they did not get data from a ground station in South Africa due to bad weather.
“Due to thunderstorm in South Africa where one of our ground stations tracking the Orbiter is located, we did not have the data from there when the engine was fired. We got the data later,” Radhakrishan said.
According to ISRO’s spaceport director M.Y.S. Prasad, two of the three phases of the Mars mission have been accomplished, with the launching of its Orbiter Nov 5 in the earth orbit and injecting it in the trans Mars orbit.
“The third important phase will be capturing of Mars orbit in September 2014, at about 500 km from the red planet’s surface, for the five scientific experiments,” Prasad told IANS on phone from Sriharikota, where the spaceport is located, about 80 km northeast of Chennai.
The space agency’s Indian Deep Space Network at Bylalu, about 40km away from Bangalore, will carry out a mid-course correction Dec 11 to ensure the Orbiter stays on course in the solar orbit.
“Three more mid-course corrections will be conducted in April, August and September 2014 during the Orbiter’s voyage in the solar orbit to the Martian orbit, about 500km from the red planet’s surface,” Karnik said.
After a nine-month long journey, the spacecraft will enter in mid-September the Mars sphere of influence, which is around 573,473km from its surface, in a hyperbolic trajectory.
“When the spacecraft is closest to Mars in mid-September, it will be captured into the Martian orbit through a crucial manoeuvre,” Karnic said.
Transition from the earth’s final orbit to solar orbit was programmed in line with sun’s gravity and laws of the universe to ensure Orbiter reaches precisely on time to sling into the Martian orbit in mid-September.
The Orbiter is carrying onboard five scientific instruments — Mars Colour Camera, Methane Sensor, Thermal Infrared Imaging Spectrometer, Lyman Alpha Photometer, and Mars Exospheric Natural Composition Analyser.
As the fourth planet from sun and behind earth, Mars is the second smallest celestial body in the solar system. Named after Roman god of war, it is also known as red planet due to the presence of iron oxide in abundance.
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.