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 spacecraft will also collect scientific information about the planet's atmosphere and surface.
The Mangalyaan probe was set to launch on 28 October, but rough weather condition in the Pacific delayed the process by a week. If the mission succeeds, ISRO will become the fourth space agency, after those in the U.S., Europe and Russia to have successfully sent a spacecraft to Mars.
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.
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.
