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Mission Mars After the premature end of the moon mission and unsuccessful bid to launch the GSLV rocket, all eyes are set on Mangalyaan, ISRO’s Mars mission. Since it got the nod only last year, questions are being raised on its hurried launch, especially in view of elections. Its success, however, will be a huge achievement for India. By Shubhadeep Choudhury THE high-profile mission of the Indian Space Research Organisation (ISRO) to Mars has followed its unsuccessful attempt to launch the GSLV rocket in August this year. The Geosynchronous Satellite Launch Vehicle (GSLV) is meant to carry heavier loads than the Polar Satellite Launch Vehicle (PSLV) that ISRO has already perfected. At present, ISRO hires launcher services for sending its heavier communication satellites to space.
Trick lies in the trajectory |
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‘Had to launch now or wait for over 2 years’
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Will ISRO get it right this
time? After the premature end of the moon mission and unsuccessful bid to launch the GSLV rocket, all eyes are set on Mangalyaan, ISRO’s Mars mission. Since it got the nod only last year, questions are being raised on its hurried launch, especially in view of elections. Its success, however, will be a huge achievement for India. By Shubhadeep Choudhury
THE
high-profile mission of the Indian Space Research Organisation (ISRO)
to Mars has followed its unsuccessful attempt to launch the GSLV
rocket in August this year. The Geosynchronous Satellite Launch
Vehicle (GSLV) is meant to carry heavier loads than the Polar
Satellite Launch Vehicle (PSLV) that ISRO has already perfected. At
present, ISRO hires launcher services for sending its heavier
communication satellites to space. The Mars mission, says a section of the space-faring community, is designed to overshadow ISRO’s failure to successfully execute the GSLV project despite working on it for two decades. Question, however, is being raised on the timing of the mission. Chandrayaan, the moon mission, took place in 2008, shortly before the 2009 general election. The Mars mission has been undertaken exactly five years later with another general election round the corner. The mission was approved in early 2012 and only about a year-and-a-half was available for the design and manufacture of the payloads. Experts say such a short preparation is simply not enough to develop payloads for a mission as complex as this. Silent on lifespan ISRO chief K Radhakrishnan has also steadfastly refused to comment about the life of the mission, taking refuge under the argument that the life of the mission would depend on the propellant consumed by the orbiter’s 440 Newton engine during its various manoeuvres. Asked what will be the lifespan of the orbiter if the fuel consumed during the manoeuvres is in accordance with ISRO’s plan, he refused to comment. This, allege sources, is to avoid the mission being branded as a failure if it comes to a premature end. It happened to Chandrayaan, which could not even complete half of its mission life of two years. ISRO, then headed by Madhavan Nair, had claimed that though the moon mission came to a premature end, it accomplished most of its objectives. The fact, however, is that the most important breakthrough associated with Chandrayaan — discovery of ice on moon — was achieved by a US payload aboard the Indian mission. Biman Nath, a Bangalore-based astrophysicist associated with the Raman Research Institute, told The Tribune that the scientific paper on the discovery of ice on moon written by US researchers had a few names from the upper echelons of ISRO out of courtesy, but they had nothing to do with the instrument or the analysis. If the lifespan of the Mars orbiter is not spelled out clearly, the planners of the mission will get more manoeuvring space for claiming the mission was a success. Among the five payloads aboard the Mars mission, the one which has got the maximum media attention is the methane sensor as it can throw light on whether there is life on the planet. If the hurriedly manufactured Indian methane sensor can prove its mettle for such an important investigation, it will certainly be considered a great feat. Importantly, NASA’s rover on Mars, Curiosity, also went through the issue in great detail recently and ruled out the existence of methane on Mars. Tech demonstrator ISRO, however, has already made it clear that the mission is primarily a technology demonstrator. Reaching the orbit of Mars — a voyage that will take the orbiter 300 days after it is given the final push on December 1 to liberate it from the Earth’s sphere of influence — will be the main accomplishment of the spacecraft. Anything achieved by any of the five scientific instruments carried by the satellite will be a bonus. Mars, by all accounts, is a tough destination and so far only the US could handle the journey with some success. The Russians have been trying their luck with Mars since the 1960s. They have attempted 19 missions to date, out of which only two were successful. The Russians also had one successful landing mission. A European mission launched in 2003 failed to land on the surface of Mars. Last year, Chinese engineers wanted to send a landing mission to Phobos, one of the two moons of Mars, with the help of a Russian launcher. But the attempt was unsuccessful as the vehicle failed to proceed beyond the Earth’s atmosphere.
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Following its copybook launch from Sriharikota on November 5, the Indian Mars probe is going round the Earth in an elliptical orbit. Periodically its orbit is being raised by firing the onboard 440 Newton engine to generate the required escape velocity from the Earth’s gravitational pull. The spacecraft will be put in a transfer trajectory toward Mars in the sixth firing of the engine. This manoeuvre, to be carried out in the early hours of December 1, will be followed by a 300-day cruise by the orbiter to arrive at the Mars sphere of influence. The engine will be fired for the last time then to slow down the spacecraft to enable its insertion in the Martian orbit. Once the spacecraft is captured in the Martian orbit, the payloads will be activated. While Chandrayaan had dropped the Moon Impact Probe on the surface of the moon, Mangalyaan (Mars craft) will not land anything on Mars. It will only orbit the red planet in an elongated orbit and take images of its surface. The main engine will not be activated after the spacecraft is inserted in the Martian orbit. Eight 22 Newton thrusters onboard the spacecraft will come into the picture then. The main function of these small engines will be to periodically raise the altitude of the spacecraft to offset the gravitational pull of Mars. When the propellant powering the thrusters gets exhausted, the mission will come to an end. The spacecraft will then gradually keep getting closer to the surface of Mars and crash on it. This, however, will take a very long time. If Mars had an atmosphere, the spacecraft would have caught fire as it came closer to the planet. Propellant consumed during the orbiter’s earth-bound manoeuvres and Martian orbit insertion is crucial. Lesser the amount of propellant consumed, better it is for the mission because the thrusters will then have access to more propellant for post-Martian orbit insertion phase operations. The engines will be operated from ISRO Telemetry, Tracking and Command Network (ISTRAC) at Peenya, Bangalore. The spacecraft leaves Earth in a direction tangential to its orbit and encounters Mars tangentially to its orbit. The flight path is roughly one half of an ellipse around the sun. Eventually, it will intersect the orbit of Mars at the exact moment that Mars is there too. This trajectory becomes possible when the relative position of Earth, Mars and sun form an angle of approximately 44 degrees. Such an alignment recurs periodically at intervals of about 780 days, providing opportunities for travelling to Mars from Earth by spending minimum energy. The next time for such an alignment will be January 2016 and later May 2018. The objectives *
Design and realisation of a Mars orbiter with capability to survive and perform Earth-bound manoeuvres, orbit insertion and on-orbit phase. *
Deep space communication, navigation, mission planning and management. *
Incorporate autonomous features to handle contingency situations. *
Explore Mars surface features, morphology, mineralogy and atmosphere by indigenous scientific instruments. What experts say *
A short space of a year-and-a-half to design and manufacture payloads is not enough for a mission as complex as this. *
The lifespan of the orbiter is not spelled out clearly, giving more manoeuvring space for success claims. Mission impossible? *
Russians have attempted 19 missions, out of which only two were successful. *
A European mission in 2003 failed to land on the surface of Mars. *
In 2013, Chinese engineers wanted to send a landing mission to Phobos, one of the two moons of Mars, with the help
of a Russian launcher, but the attempt failed. On a shoestring *
ISRO has spent a mere Rs 460 crore to launch Mangalyaan. The amount is trifling compared with missions of other countries that cost billions of dollars. *
Curiosity, the US mission to Mars launched in 2011, cost $2.5 billion (Rs 15,663.75
crore). * The secret of ISRO’s success in keeping the cost low is the modular approach it adopted. For instance, the technology of Vikas engine used in the PSLV was developed by ISRO while working with the French in the 1970s. There was no transaction of money. ISRO has since produced 120 such engines with Indian materials and fabricated wholly in the country. For every successive launch, the base had been the previous launch technology that had been modified and built upon. The same modular tactic is used for satellites. *
When ISRO conducts ground tests, which are time consuming and expensive, it limits the tests to a minimum and tries to get the best out of each test. *
For transferring Mangalyaan to Mars’ orbit, ISRO has used undisclosed strategies to bring down fuel consumption. Its scientists sometimes work 20 hours a day. Effective time management brings down the mission cost. *
While NASA and the European Space Agency usually make three models of the spacecraft, ISRO modelled everything on software and built only the final model.
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‘Had to launch now or wait for over 2 years’ ISRO chief K Radhakrishnan spoke to The Tribune on a host of issues, including the timing of the mission and its usefulness.
What do you have to say about the timing of the mission? After the Prime Minister made an announcement about the mission in August last year, we could launch the orbiter in the next 15 months’ time. If we had not done so, the next opportunity for a Mars mission would have come only after a period exceeding two years. We deserve credit for executing the launch in such a short notice. Huge sums of money are spent on space programmes when many people do not have access to even basic necessities like food and water. The Indian space programme is integrally linked with requirements of ordinary people. The bulk of ISRO’s budget is spent on developing space applications like remote sensing and communication satellites which have everyday use for the common people. Data provided by three ISRO satellites was helpful in reducing the losses during the recent cyclone that hit Andhra Pradesh and Orissa. What is the usefulness of the mission? The experiment with the autonomy given to the Mars orbiter will come in handy for developing remote sensing satellites in future. These satellites will also have autonomy to a considerable extent. The Mars mission, which is the first interplanetary mission undertaken by India, will also attract young people to space science. What about Chandrayaan 2? Chandrayaan 2 will be carried out with lander and rover developed by us and not by Russians as planned originally. What about the launch of the aborted GSLV-D5 rocket? In all likelihood the launch will take place on December 15 this year.
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