A Methane Sensor, one of the five payloads (scientific instruments) onboard the spacecraft, would look to detect the presence of the gas, MOM Project Director Arunan S said.
He said the sensor was aimed at understanding whether life existed on Mars or if it would have life in future.
"Methane is fundamentally base for life on any planet," he said.
M Annadurai, Programme Director, IRS & SSS (Indian Remote Sensing & Small, Science and Student Satellites), said: "Most probably we will be able to answer whether there is presence of Methane. If it's there, yes; if it's not, not there. If it's available, where it's available".
After a media preview of the Mars orbiter at ISRO Satellite Centre here, where it is being given final shape, officials of the space agency indicated that the aim is to launch the mission on October 21, weather permitting.
The launch window is from October 21 to November 19.
MOM is a Rs 450 crore mission -- Rs 110 crore for building PSLV-C25 that would launch the Rs 150 crore spacecraft, with the remaining amount spent on augmenting
ground segment, including those required for deep space communication.
Once launched from the spaceport of Sriharikota, the spacecraft would go around the earth for 20-25 days before embarking on a 9-month voyage to Mars. The minimum life of the spacecraft around Mars is six months but it would certainly outlive it, as similar satellites orbited by other countries have sometimes lasted six-seven years, Arunan said.