All about the Mars Orbiter Mission

The Mars Orbiter Mission (MOM) is India’s first planetary mission. The success of this mission has made ISRO the fourth space agency to reach Mars after Soviet Space Program, NASA and European Space Agency. The notable fact is that ISRO launched the satellite successfully in its first attempt.

How it all began

After the lunar launch satellite in 2008, the MOM mission gained momentum after the Indian government approved the project on 3 August 2012. The approval was given after ISRO completed a study worth Rs 125 crore required for the orbiter. The on-orbit mission life of the Mars Orbiter is six-to-ten months. Assembly of the PSLV-XL launch vehicle, designated C25, started on 5 August 2013.

The mounting of the five scientific instruments was completed at ISRO Satellite Centre and the finished spacecraft was shipped to Sriharikota on 2 October 2013 for integration to the PSLV-XL launch vehicle. The satellite's development was put on fast-track and completed in a record time of 15 months.

Expenditure incurred for the mission

The MOM is hailed as the cheapest Mars mission till date and the total cost of the mission was approximately Rs 450 crore. The low cost of the mission was ascribed by K. Radhakrishnan, the chairman of ISRO, to various factors, including a modular approach, few ground tests and long working days for scientists. Lower worker costs, home-grown technologies, simpler design and significantly less complicated payload than NASA's MAVEN helped in cutting costs.

Objectives of MOM:

• Design a Mars orbiter with a capability to perform Earth-bound maneuvers, with a cruise phase of 300 days, Mars orbit insertion / capture, and on-orbit phase around Mars
• Accomplish deep-space communication, navigation, mission planning and management and incorporate autonomous features to handle contingency situations
• To explore surface features of Mars like morphology, mineralogy and Martian atmosphere using indigenous scientific instruments
• Features of the Spacecraft
• The lift-off mass is 1,350 kg (2,980 lb), including 852 kg (1,878 lb) of the propellant.
• The bus of the spacecraft is a modified I-1 K structure bolstered by propulsion hardware configuration with specific improvements and upgrades needed for a Mars mission.
• The satellite structure is constructed with aluminum and composite fiber reinforced plastic (CFRP) sandwich construction.
• The spacecraft is powered by solar panels of 1.8 m × 1.4 m (5 ft 11 in × 4 ft 7 in) each (7.56 m2 (81.4 sq ft) total) for a maximum of 840 watts of power generation in the Mars orbit. Electricity is stored in a 36 Ah Lithium-ion battery
• A liquid fuel engine with a thrust of 440 newtons is available for orbit raising and insertion into the Mars orbit. The orbiter also has eight 22-newton thrusters for altitude control.

Launch of MOM

ISRO looked to launch MOM using its Geosynchronous Satellite Launch Vehicle (GSLV), but had previously failed twice. Hence, ISRO opted the less-powerful Polar Satellite Launch Vehicle (PSLV). Since the PSLV was not powerful enough to place MOM on a direct-to-Mars trajectory, the spacecraft was launched into the highly elliptical earth’s orbit, which then used its own thrusters over multiple perigee burns to place itself onto the trans-Mars trajectory.

The launch was postponed by a week due to the delay of a crucial telemetry ship reaching Fiji. The launch was rescheduled for 5 November 2013. ISRO's PSLV-XL placed the satellite onto the earth’s orbit on 5 November 2013. On 30 November 2013, a 23-minute engine firing initiated the transfer of MOM away from earth’s orbit onto a heliocentric trajectory toward Mars. The probe travelled a distance of 780,000,000 kilometres (480,000,000 mi) to reach Mars.

Mars orbit insertion

The plan was to insert the orbiter into the Mars orbit on 24 September 2014, approximately two days after the arrival of NASA's MAVEN orbiter. The 440N liquid apogee motor was successfully test-fired on 22 September for 3.968 seconds; about 41 hours before actual orbit insertion.

On 24 September 2014, the satellite communication changed over to the medium gain antenna. Forward rotation began and locked the position to fire, an altitude control maneuver took place with the help of thrusters after the eclipse and the LAM (Liquid Apogee Motor) was put in motion. A reverse maneuver later, the spacecraft successfully entered the Martian orbit.

Present status

The orbit insertion put MOM in a highly elliptical orbit around Mars, with a period of 72 hours 51 minutes 51 seconds, a periapsis of 421.7 km and apoapsis of 76,993.6 km. At the end of the orbit insertion, MOM was left with 40 kg (88 lb) of fuel on board, more than the 20 kg (44 lb) believed necessary for a six-month mission. On 28 September 2014, MOM controllers published the spacecraft's first global view of Mars. The image was captured by the Mars Colour Camera (MCC).

On 4 March 2015, the ISRO reported that MOM's methane sensors were functioning normally and are studying Mars' albedo, the reflectivity of the planet's surface. The Mars Colour Camera was also returning new images of the Martian surface. ISRO is in a plan to send a follow-up mission called Mangalyaan 2 with a greater scientific payload to Mars between 2018 and 2020. This mission will likely consist of a lander and rover, rather than just being an orbiter.