India is going to Mars. On November 5 the Indian Space Research Organization (ISRO) initiated launch of MOM, its Mars Orbiter Mission, informally known as Mangalyaan. The probe launched from a pad in Sriharikota, Andhra Pradesh, India, using a Polar Satellite Launch Vehicle (PSLV,) an expendable launch platform developed by ISRO.
The MOM launch represents India’s first attempt at interplanetary travel. The spacecraft had a lift-off mass of just less than 3,000 pounds, which included over 1,800 pounds of liquid propellant. The satellite body is constructed from aluminum and composite fiber reinforced plastic sandwiched together. Electrical power is supplied by three solar arrays, with storage handled by a 36 Ah Li-ion battery system.
The MOM payload is scientific in nature, consisting of five distinct instrument systems. The Indian Mars science package will consist of a Lyman-Alpha photometer, a methane sensor, a quadrupole mass analyzer, a color camera operating in the visible light spectrum and a thermal infrared imager.
The photometer will be used to measure the abundance of hydrogen and deuterium in Mars’ upper atmosphere, which will aid in estimating water loss. The methane sensor is important because atmospheric methane is often, though not solely, produced by living microorganisms. Volcanism is another possible source for production and maintenance of methane in the Martian atmosphere. The mass analyzer will be used to measure the neutral composition of atmospheric particles, while the two imaging systems will provide visual and thermal pictures of the planetary surface, allowing insight into terrestrial composition and mineralogy.
Getting a spacecraft to traverse interplanetary space and arrive at a specific location is tricky business. Two-thirds of all Mars missions have succumbed to failure at one stage of the journey or another. The task requires a complex mixture of technical expertise that has proven difficult to achieve.
India originally intended to launch the MOM on a Geosynchronous Satellite Launch Vehicle (GSLV), but that innovative platform failed twice due to engine issues. ISRO decided to go with the PSLV launch system because if they missed the launch window it would have been several years before the MOM could launch.
Due to PSLV power limitations, the ISRO could not launch on a direct-to-Mars trajectory. Instead, India launched the spacecraft into a high-Earth orbit and used a series of gravity-assisted maneuvers to leverage the unit into an interplanetary trajectory.
On November 20th, the PSLV ‘s engines fired for 23 minutes to transfer the MOM out of Earth orbit and into a heliocentric orbit that would lead it towards Mars. India, with assistance from NASA telemetry, will monitor the 484 million mile journey to the Red Planet. There are several course corrections that will have to take place in 2014 to keep the spacecraft heading towards Mars. Current projections call for the MOM unit to enter Mars orbit in September 2014.
If the ISRO MOM successfully reaches the Red Planet, it will make India the fourth space program to do so; the others are the U.S., the European Space Agency and the Soviet-era space program.
The MOM, if successful and on-time, will enter Mars orbit two days after the American MAVEN orbiter. The two craft will produce complementary data streams that will greatly increase our collective understanding of our neighbor planet. India has plans for other Mars launches when this sequence is complete.
By Mark Clarke