Mars orbiter's first course correction manoeuvre successful

Three more corrections are planned during the satellite's journey to the orbit of Mars to prevent it from straying from trajectory

Published: Wednesday 11 December 2013

The Indian Space Research Organisation carried out the first trajectory correction manoeuvre (TCM) of its orbiter to Mars at 6.30 am Wednesday morning. The orbiter was catapulted towards Mars on December 1. The first course correction in the orbiter's journey has been carried out early to ensure that it does not stray too far from its predetermined path. A total of four corrections are planned in the orbiters' 300 day journey to the orbit of Mars During TCM, the orbiter was first oriented to ensure an effective course correction. The orbiter has eight thrusters on board which were fired for 40.5 seconds to correct the course. Multiple thrusters ensure that the manoeuvre is precise. At present, the orbiter is 2.9 million kilometres away from Earth and signals from here take about 20 seconds to reach the orbiter and return. After the manoeuvre, the orbiter would be reoriented to ensure that it maintains continuous communication with Earth and the solar panels work efficiently. As India's satellite journeys to the Red Planet, new information about it has been received from other satellites sent out earlier by other countries to the planet. Six papers were published in the journal Science on December 9, detailing the findings of Curiosity rover which landed in the Gale crater on August 2012. Is Mars habitable? These studies show that the five-metre-deep depression known as Yellowknife Bay has fine, medium and course-grained sedimentary rocks. This suggests a lake existed there for tens of thousands of years. This lake had neutral pH, low salinity and key biological elements, such as carbon, hydrogen, oxygen, sulphur, nitrogen and phosphorous. These conditions make it hospitable to prokaryotic microorganisms. An analysis of two sedimentary rock samples, known as John Klein and Cumberland show that contrary to earlier assumptions that such minerals formed about 4.1 billion years ago, the formation of Yellowknife Bay continued into the subsequent period too. A measure radioactive isotopes in the Cumberland sample suggest that it was deposited about 4.21 billion years ago (plus or minus 350 million years)ÔÇöshortly after the Gale impact ÔÇôand that it has only been exposed on the surface of the planet for about 78 million years (give or take 30 million years). This may provide the most accurate ages for other regions of the planet. These samples are likely to have formed under extremely cold and arid conditions, highlighting the environment that existed on Mars billions of years ago. An analysis of the amount of radiation from cosmic rays and other energetic particles that struck the Martian surface for 300 days was also reported. This might help scientists figure out whether the planet is habitable. Calculations show that a 500-day mission on the surface would bring the total exposure to around 1 Sievert (Sv). Studies on Earth have shown that exposure to 1 Sv is associated with a five per cent increase in fatal cancer risk.

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