New Delhi - India's launches its first mission to Mars on Tuesday, aiming to become the only Asian nation to reach the planet with a programme designed to showcase its low-cost space technology.A rocket carrying a 1.35-ton unmanned probe will blast off at 14:38 (09:08 GMT) from the Sriharikota spaceport off the southeast coast, beginning a 300-day journey to study the Martian atmosphere."The countdown is progressing well, as scheduled," said Deviprasad Karnik, spokesperson for the Indian Space Research Organisation (Isro). "The weather is normal. Slightly cloudy but no problem."The Mars Orbiter Mission, known as "Mangalyaan" in India, was announced 15 months ago by Prime Minister Manmohan Singh shortly after a Chinese probe flopped when it failed to leave Earth's atmosphere.The timing led to speculation that India was seeking to make a point to its militarily and economically superior neighbour, despite denials from Isro.Second stage"We are in competition with ourselves in the areas that we have charted for ourselves," said Isro chair K Radhakrishnan last week. "Each country has its own priorities."The golden-coloured probe, about the size of a small car, has been hurriedly assembled and will be carried by a rocket much smaller than American or Russian equivalents.Lacking the power to fly directly, the 350-ton launch vehicle will orbit Earth for nearly a month, building up the necessary velocity to break free from our planet's gravitational pull.Only then will it begin the second stage of its nine-month journey which will test India's scientists to the full, five years after they sent a probe called Chandrayaan to the moon.A study of data from Curiosity published in September found that the rover had detected only trace elements of methane in the Martian atmosphere."Remember that it [Curiosity's methane reading] is for a single spot. One point doesn't make it a story for the whole planet," said Goswami, who was lead scientist for the moon mission.Nasa, which will launch its Maven probe to study the Mars atmosphere on 18 November, is helping Isro with communications. Two Indian ships stationed in the Pacific will also assist with monitoring.