INDIA'S MARS ORBITERS MISSION

 

PSLV puts Mars orbiter precisely into earth-orbit; trip to the Red Planet will take more than 300 days

The nation’s prestigious interplanetary mission to Mars, 40 crore km away, got off to a flying start on Tuesday when the Indian Space Research Organisation’s trusty Polar Satellite Launch Vehicle (PSLV-C25) roared off the first launch pad of the spaceport at Sriharikota at 2.38 p.m. and put the Mars orbiter precisely into its earth-orbit about 44 minutes later.

This was the first crucial and difficult step in the ISRO’s Mars Orbiter Mission. However, the XL version of the PSLV achieved it with aplomb. The elliptical orbit achieved was so accurate that against the predicted perigee of 250 km and an apogee of 23,500 km, it went into an orbit of 246.9 km x 23,566 km.

The spacecraft first going into orbit around the earth signalled the start of its 300-day voyage to the Red Planet. If everything goes well during this complex and challenging journey through deep space, it will be put into the Mars orbit on September 24, 2014.

Mission highlights

Two mission highlights are: it was the longest PSLV mission at 44 minutes — the previous missions lasted about 18 minutes, and this was the silver jubilee lift-off of the PSLV. Out of the 25 launches, 24 had been successful in a row.

Suspense filled the newly-built Mission Control Centre (MCC) when there was a long coasting phase of 25 minutes between the PSLV’s third stage burnout and the fourth stage ignition.

Tension gripped the MCC again for about half-a-minute for it was only 37 seconds after the fourth stage burnout that the spacecraft was put into orbit. But all this was as planned.

The ISRO scientists’ cup of joy overflowed when M.S. Pannirselvam, Range Operations Director, PSLV-C25, announced tersely from the MCC, “Spacecraft separation achieved. It has been successfully put into orbit.”

Asked later how he felt when he made the announcement, he said, “We had no feeling. We were doing our job.”

Applause erupted when ISRO Chairman K. Radhakrishnan, who did not hide his joy, turned towards his colleagues in the MCC and acknowledged their cheers with folded hands. He called the flight a copybook and textbook mission. It was a new and complex mission in design and execution, he said.

Project Director of Mars Orbiter S. Arunan called it an “excellent mission.” The primary and secondary panels and the high gain antenna of the spacecraft had been deployed. “The spacecraft is in good heath,” he said.

Yash Pal, former Member of the Space Commission, called the successful mission ISRO’s “very very special gift to the nation.”

Long way to go

All former and present brass of ISRO tried to temper the delight by cautioning that “there was a long way to go in time and distance” before the orbiter was put into the Martian orbit in September 2014. They included present top engineers S. Ramakrishnan, M.Y.S. Prasad, A.S. Kiran Kumar, S.K. Shivakumar, M.C. Dathan, P. Kunhikrishnan and the former ISRO chairmen, U.R. Rao and K. Kasturirangan. They emphasised that “while the first job has been successfully done, a long journey lies ahead.”

Objectives
The primary objective of the Mars Orbiter Mission is to showcase India's rocket launch systems, spacecraft-building and operations capabilities. Specifically, the primary objective is to develop the technologies required for design, planning, management and operations of an interplanetary mission, comprising the following major tasks
    Design and realisation of a Mars orbiter with a capability to perform Earth bound manoeuvres, cruise phase of 300 days, Mars orbit insertion / capture, and on-orbit phase around Mars.
    Deep space communication, navigation, mission planning and management.
    Incorporate autonomous features to handle contingency situations.

The secondary objective is to explore Mars' surface features, morphology, mineralogy and Martian atmosphere using indigenous scientific instruments.

Spacecraft

The spacecraft structure and propulsion hardware configurations are similar to Chandrayaan 1, India's first successful robotic lunar orbiter that operated from 2008 to 2009, with specific improvements and upgrades needed for a Mars specific mission.

Mass
    The lift-off mass was 1350 kg, including 852 kg of propellant mass.
Dimensions
    Cuboid in shape of approximately 1.5 m
Bus
    The spacecraft's bus is a modified I-1 K structure and propulsion hardware configurations similar to Chandrayaan 1, India's successful lunar orbiter that operated from 2008 to 2009, with specific improvements and upgrades needed for a Mars mission. The satellite structure is of aluminum and composite fiber reinforced plastic (CFRP) sandwich construction.
Power
    Electric power is generated by three solar array panels of 1.8 m X 1.4 m each (7.56 m2 total), for a maximum of 840 W generation in Martian orbit. Electricity is stored in a 36 Ah Li-ion battery.

Propulsion
    Liquid fuel engine of 440 N thrust is used for orbit raising and insertion in Martian orbit.
Communications
    Two 230 W TWTAs and two coherent transponders. The antenna array consists of a Low-gain antenna, a Medium-gain antenna and a High-gain antenna. The High-gain antenna system is based on a single 2.2 meter reflector illuminated by a feed at S-band. It is used to transmit and receive the telemetry, tracking, commanding and data to and from the Indian Deep Space Network.

Payload

The 15 kg (33 lb) scientific payload consists of five instruments:

Atmospheric studies

    Lyman-Alpha Photometer (LAP) — a photometer that measures the relative abundance of deuterium and hydrogen from Lyman-alpha emissions in the upper atmosphere. Measuring the deuterium/hydrogen ratio will allow the amount of water loss to outer space to be estimated.
    Methane Sensor For Mars (MSM) — will measure methane in the atmosphere of Mars, if any, and map its sources.

Particle environment studies

    Mars Exospheric Neutral Composition Analyzer (MENCA) — is a quadrupole mass analyzer capable of analyzing the neutral composition of particles in the exosphere.

Surface imaging studies

    Thermal Infrared Imaging Spectrometer (TIS) — will measure the temperature and emissivity of the Martian surface, allowing for the mapping of surface composition and mineralogy of Mars.
    Mars Color Camera (MCC) — will provide images in the visual spectrum, providing context for the other instruments