Three more corrections are planned during the satellite's journey to the orbit of Mars to prevent it from straying from trajectory
.jpg "Image shows trajectory correction manoeuvres planned by ISRO to keep orbiter on course (image courtesy ISRO)")
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 was 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)—shortly after the Gale impact –and 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.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
.png)
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.