Countdown begins for Mars mission

Spacecraft is scheduled to take off at 14:38 hours on Tuesday, is likely to reach its destination sometime in September 2014

The 56 hours and 30 minutes’ countdown to the Mars Orbiter Mission  of the Indian Space Research Organisation (Isro) commenced on Sunday at the Sriharikota space station, about 100 km from here.

The countdown began at 6.08 am, for the Polar Satellite Launch Vehicle (PSLV) C25, which will carry the Mangalyaan satellite into space and on to an orbit around Mars. Isro said things were proceeding smoothly.

The PSLV-25 spacecraft is scheduled to take off at 2.38 pm on Tuesday from the Satish Dhawan Space Centre (SHAR) at Sriharikota, off the southern Andhra coast. The spacecraft will carry India’s first inter-planetary satellite.

In the past 60 days, every part was checked and integrated, then the satellite was integrated and tests were conducted, said an Isro official. The Launch Authorisation Board gave approval on Friday for the launch, after a successful rehearsal.

The spacecraft is expected to take a little over 40 minutes to inject the satellite into the Earth’s orbit from the time it takes off. The spacecraft is a special version of the PSLV, also used to launch Isro’s Chandrayaan-1 lunar orbiter mission in 2008 and, since then, a communications satellite and two Earth-observation satellites. The Tuesday launch will be the 25th flight of the PSLV, which has succeeded in all its missions except its maiden flight in 1993.

Isro’s deep space communications facility at Byalalu in Karnataka and the US National Aeronautics and Space Administration’s ground stations in Goldstone (California), Madrid (Spain) and Canberra (Australia) will help Isro achieve precision tracking of the spacecraft during its voyage to Mars and its injection into an orbit around the planet.

Two Shipping Corporation of India vessels, Nalanda and Yamuna, have taken positions to track the PSLV flight from the southern Pacific.

“They will look for two crucial events during the launch -- ignition of the fourth stage of the PSLV and separation of the spacecraft as it is injected into Earth-orbit,” Isro Chairman K Radhakrishnan said.

The Mars orbiter will be the first Isro craft to exit the sphere of the Earth’s influence, moving 925,000 km to then enter a heliocentric cruise phase, where the gravitational tugs of the Sun and the other planets will dominate. It would be a 10-month journey. Less than half the 50-odd spacecraft sent by other countries towards Mars have been able to complete the journey.

Radhakrishnan recently said the first major challenge would be on December 1, at 42 minutes after midnight, when the orbiter will be given a ‘trans-Mars injection’ after it moves away from the Earth’s sphere of influence and enters a heliocentric orbit, also called the trans-Martian orbit.

The Mars Orbiter has to go a distance of 200-400 million km.  

The spacecraft is expected to approach Mars in September 2014 and at that point, the Orbiter has to be slowed or it will just disappear in space, he said.
THE BIG MISSION

• The 56 hr 30 min countdown of Mission commenced at 06:08 hrs (IST).
• Mixed Oxides of Nitrogen (MON) filling of PS4 completed at 17:00 hrs (IST).
• Mono Methyl Hydrazine (MMH) filling of Reaction Control Thrusters (RCT) completed.
• Mono Methyl Hydrazine (MMH) filling completed.
• Propellant filling operations of Fourth Stage (PS4) are in progress.