A second Indian Mars orbiting mission plan has just been set in motion.

Nearly three years after it launched a world record making MOM (Mars Orbiter Mission) the Indian Space Research Organisation has invited Indian planetary scientists from the academia and research bodies to suggest which aspects of Mars should now be studied, along with the instruments they can provide for MOM-2.

Although a second Martian venture has been in the air, the latest `Announcement of opportunity' or AO is the first formal whiff of it. The scientists have been asked to make their proposals by September 6.

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An official privy to the developments said the exact date and details of MOM2 would depend on the proposals that would come in. He estimated that "We should ideally have the total picture of the mission by the end of this year or at least before the 2017 Budget." Payloads and experiments would be the focus of the second mission.

MOM is famous for being the first mission by any country to reach Mars in the very first attempt. Russia, the US and Europe have failed in their debuts.

Space agencies get the best opportunity to send a spacecraft to Mars once in 26 months based on the relative positions of Earth and Mars, which constantly move around Sun.

Considering that India and the US both sent their respective Mars missions days apart in November 2013, the next two opportunities were around January 2016 (considered not very conducive) and around March 2018.

Why a second Martian mission? Scientists believe that the atmosphere, land and minerals on Mars, which has similarities with Earth, may answer questions on how planets evolved, whether there is life elsewhere in the solar system and perhaps suggest the future of Earth itself.

Questions remain

U.R.Rao, cosmologist, former ISRO Chairman and chairman of ADCOS (Advisory Committee for Space Science) that shapes Indian planetary pursuits, said Mars needs a closer look than what MOM has done. "We still do not know many things about Mars. Methane study [that MOM carries] still is important, and also a study of the Martian dust and its ionosphere."

MOM, Dr. Rao said, was a "great engineering feat" that taught India how to reach the red planet and has sent down good pictures of Mars across millions of kilometres. The MOM-2 spacecraft should ideally have an orbit of 200 km x 2,000 km. It should take better experiments with sharper instruments along and use the bigger GSLV rocket to propel it. Last time, ISRO used the light-lift PSLV.