India's Stint With The Red Planet

The much awaited Mars Orbiter Mission (MOM) or Mangalyaan has been delayed by a week and the new launch date is November 5^th (mangalwar) 14:36 IST from the Satish Dhawan Space Centre, Sriharikota. India is using its most trusted launch vehicle, PSLV-C25 an XL variant of the launcher. For any nation– For any nation, initiation of any project for Mars is technologically exacting as it demands understanding and executing interplanetary aerodynamics with extreme precision. It throws up a challenge to India to develop the required technical skills across a wide spectrum of cutting edge technologies and to test them. Moreover, it will be India’s first attempt to understand and work through the deep interplanetary region and Martian gravitational force as this satellite has to be placed 360,000,000 Km from earth. For the satellite to be placed in Mars orbit, it has to overcome the earth’s gravitational force and enter the heliosphere, the region of Sun’s gravity before entering the Mars gravitational field. It is 300 days journey with three distinct phases-Geo-centric phase, Heliocentric phase and the most crucial Martian phase.

In order to take the advantage of the unique planetary position India planned to launch Mangalyaan on October 28^th . The decision to delay the launch of the Mars Orbiter is due to the bad weather conditions in the South Pacific Ocean. Two ships SCI Nalanda and SCI Yamuna leased from Shipping Corporation of India to study the crucial phase of satellite ejection. Nalanda carrying the satellite tracking system has failed to reach Fiji on Oct 21^st. From Fiji both ships have to travel to their designated locations, for tracking the position of the rocket. While one ship tracks ignition, other will track the satellite separation. The crucial journey of the satellite from Earth to Mars will be tracked by the Indian Deep Space Network (IDSN) from Baylalu on the outskirts of Bengaluru. The time of Mars capture, navigation and communication will be tracked by the 70m antennae of NASA’s deep space network located at Canberra. NASA’s Jet Propulsion laboratory (JPL) has promised to provide navigation and communication support to this mission with their deep space network facilities. ISRO had some tense moments before launch following the financial shutdown in US as it relied on NASA’s deep space network. But NASA allayed ISRO’s fears and assured complete support.

Initially ISRO planned to launch a 500kg satellite with scientific payload of 25kg using the GSLV, but due to its failure they have scaled down the project. The current Mars Orbiter has 15kg payload which contains five scientific instruments to map, scan and analyse the surface of mars and its atmosphere. These include a methane scanner, capable of scanning the entire Martian disc within six minutes and a mars colour camera. Initial reports on Martian atmosphere suggested the presence of Methane clouds. Methane gas analysis is done as it indicates the existence of life on Mars. But presence of Methane gas on Mars is still largely debated. The space craft Curiosity of NASA which landed on the Gale Crater has failed to detect methane in six samples. The upper limit of methane in the atmosphere was estimated to be 1.3 parts per billion by volume which is several folds lesser than the estimates made by satellite and telescopic observations. In March 2003 a research team led by Micheal J Mumma of NASA Goddard Space flight Centre has observed a big plume emanating gases from certain locations. Based on those observations they have accounted for the presence of 19,000 tonnes of methane. But the amount has become half by January 2006. Scientists believed that the sunlight might have caused the breakdown of the gas. Since the lifetime of methane gas is more than 300 years this observation is highly contested. Methane is much lighter and might have escaped into the higher levels of the atmosphere composed mostly of carbon dioxide and perhaps Curiosity couldn’t detect it. Indian sensor aboard can detect the methane up to a level of 10 parts per billion of volume. If the methane gets mixed with the Martian atmosphere, then it may not be able to record any measurements. But if indeed any sporadic eruptions occur when the Orbiter races around the planet, sensor can detect the gas erupting from the plumes, subsequently providing valuable inputs to solve the methane puzzle of Mars.

The Liquid Apogee Motor will propel the Orbiter from earth’s orbit hurtling it past towards Mars. The space craft will be placed in an elliptical orbit at closet distance of 377 km from Mars. The main focus is to study climate, geology of Mars, to assess its suitability for life by exploring the presence of groundwater aquifers, effect of solar wind on Mar’s atmosphere and the surface magnetic field. By Nov 30^th Orbiter has to leave the earth’s sphere of influence, otherwise it has to wait for 26 months for the next launch. The present mission is more challenging when compared to Chandrayaan, as it has argument of perigee of 270 degrees, which requires longer flight and different trajectory. It is to use minimum fuel to transfer from Earth’s orbit to Mar’s orbit.

The major challenges in the current interplanetary mission are critical mission operations and stringent requirements of propulsion, communication and other bus system of space craft. The basic technological learning from this mission are designing and realising a space craft capable of reaching Mars (Martian transfer trajectory), and orbiting around Mars (Mars Orbit insertion) which will take about 9 months after circling around the Earth for 20-22 days. The maximum earth to mars Round trip Light Time (RLT) is 42 min. It takes 21 min for a signal from earth to reach mars and vice versa. Hence communication with the satellite becomes extremely daunting task. The satellite has to be loaded with commands in advance so that it can take care of itself.

The successful launch of the 1350kg of Mars Orbiter would ensure India’s entry into the elite club of nations -USA, Russia and Europe, which have made explorations to the red planet. US, Russia and European Space Agency (ESA) are the predecessors who have either independently or in collaboration have placed their spacecrafts in the celestial bodies. This mission assumes greater importance as Asian giant China in 2011 had to abort the launch of its space craft Yinghou-1 to Mars due to a technical problem. World media is wondering whether this is beginning of an ongoing Asean space race between China, Japan and India.

Earliest attempts to explore the red planet were the result of the ongoing space race between the US and USSR in early 1960. USSR failed to launch its satellite Marsnik 1 in 1960 but US’s Mariner 4 could fly by the Mars planet. NASA has been successful in sending two rover crafts to Mars, Curiosity and Pathfinder that have started probing the Martian surface, its atmosphere, soil composition and other aspects.

 

 

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