India's launches its first mission to Mars on Tuesday, aiming to become the only Asian nation to reach the Red Planet with a programme designed to showcase its low-cost space technology.
A rocket carrying a 1.35-tonne unmanned probe will blast off at 02:38pm (0908 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, spokesman 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.
"We are in competition with ourselves in the areas that we have charted for ourselves," ISRO chairman K. Radhakrishnan told AFP last week. "Each country has its own priorities."
The golden-coloured probe, about the size of a small car or very large refrigerator, 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-tonne 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.
More than half of all Mars projects have failed, including China's in 2011 and Japan's in 2003. Only the United States, Russia and the European Union have successfully reached there.
"I was very nervous during the moon mission, but after seeing the precision with which our people took Chandrayaan to the orbit I have to be confident," top Indian space scientist Jitendra Nath Goswami told AFP.
The total cost of the project is just 4.5 billion rupees ($73 million), a fraction of foreign equivalents.
There have been recent setbacks for India, however, including when Chandrayaan lost contact with its controllers in 2009 and when a new larger launch vehicle blew up after take-off in 2010.
India has never before attempted an inter-planetary journey which has required the development of technology enabling the probe to run autonomously. Communication signals take 12 minutes to travel between Earth and Mars.
"The biggest problem is to understand the navigation issue from the earth's orbit to the Martian orbit," ISRO chief Radhakrishnan told AFP.
The programme also has to contend with domestic critics who say a country that struggles to feed its people adequately and where more than half have no toilets should not be splurging on space travel.
"An improvement of basic social indicators should be the priority and then we can have many missions to Mars," activist Shivani Chaudhry from the New Delhi-based Housing and Land Rights Network told AFP.
ISRO counters that its technology has helped with economic development through satellites which monitor weather and water resources, or enable communication in remote parts of the country.
The Bangalore-based organisation and its 16,000 staff also share their rocket technology with the state-run defence body responsible for India's rapidly evolving missile programme.
The United States is the only nation that has successfully sent robotic explorers to land on Mars, the most recent being Curiosity, a nearly one-tonne vehicle which touched down in August 2012.
One of its discoveries appeared to undercut the purpose of the Indian mission which is to find evidence of methane which would lend credence to the idea of Mars supporting a primitive form of life.
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 own probe to study Mars on November 18, is helping ISRO with communications. Two ships stationed in the Pacific will also assist with monitoring.
[Image via Agence France-Presse]