Bangalore, April 5, 2013:
Hectic efforts are on at Indian Space Research Organisation (ISRO) to realise the Mars Orbiter Mission (MOM) spacecraft for launch in October 2013 onboard Polar Satellite Launch Vehicle (PSLV-XL). This is the immediate next available opportunity for such a mission as Earth and Mars would be coming closer then. After leaving earth orbit in November 2013, MOM spacecraft will cruise in deep space for 10 months using its own propulsion system and will reach Mars (Martian transfer trajectory) in September 2014.
The spacecraft subsequently is planned to enter into a 372 km by 80,000 km elliptical orbit around Mars. The 1350-kg MOM spacecraft will carry five instruments to study Martian surface, atmosphere and mineralogy.
This would be India’s first mission to a distant planet. MOM — ISRO’s first interplanetary mission to planet Mars — is India’s next challenging technological mission out of the Earth’s gravitational field.
The major demands will be critical mission operations and stringent requirements on propulsion, communications and other bus systems of the spacecraft. The primary driving technological objective of the mission is to design and realise a spacecraft with a capability to reach Mars (Martian transfer Trajectory), then to orbit around Mars (Mars Orbit Insertion) which will take about nine months time.
Yet another technological challenge is to realise related deep space mission planning and communication management at a distance of nearly 400 million km. The PSLV-XL will be used to inject the spacecraft from SDSC, SHAR in the 250 X 23000 km orbit with an inclination of 17.864 degree. As the minimum energy transfer opportunity from Earth to Mars occurs once in 26 months, the opportunity in 2013 demands a cumulative incremental velocity of 2.592 km/sec.
Preliminary Design Reviews of all the spacecraft systems and payloads have been completed. The structure has been delivered to clean room and the propulsion system integration is in the final stage. All payloads are in the advanced stage of development and expected to be delivered for integration by end-April 2013. The ground segment elements at Indian Deep Space Network (IDSN) at Byalalu and S- band sea-borne terminals are getting geared up for the mission.
“The primary objective of this challenging mission is to establish the Indian technological capabilities to reach the orbit of Mars. Also, it is planned to undertake a few scientific studies during the orbital life of the spacecraft, using Indian instruments onboard”, says ISRO Chairman K Radhakrishnan.
“The opportunity of launching a probe to Mars appears every 26 months — when the Earth and Mars come relatively close to each other. Hence, time is the essence for availing this opportunity. A number of technological challenges need to be negotiated for a successful Mars mission”, he adds.
First, the spacecraft should be provided with augmented radiation shielding for its prolonged exposure in the Van Allen belt.
Secondly, due to the long range of the order of 55-400 million km from Earth to Mars, there is a communication delay of 20 minutes one way itself. This necessitates high level of onboard autonomy to be built within Mars orbiter. For Chandrayaan-1, ISRO had to deal with only four lakh kms.
Thirdly, and most importantly, — the robustness and reliability of propulsion system has to be one order higher as after leaving the orbit of Earth the system would require to work after almost 300 days. And during this voyage, the system needs to maintain complete integrity so as to capture the Martian orbit.
Capture of the Mars orbit or the Martian insertion is the critical event that would determine the success of this mission.
This mission, if successfully executed, would pave way for exciting opportunities for a new era of planetary exploration.
