India's 50-year-old space odyssey will start a new chapter this week when an indigenously built spacecraft — affectionately called MOM ( Mars Orbiter Mission ) — attempts to enter the orbit around the Red Planet after a 680-million-km journey. The orbiting mission will take pictures and collect scientific data for about six months. The most nail-biting phase will begin early Wednesday when it executes the crucial Mars orbit insertion, a stage at which most missions have failed. Isro chairmanspeaks about the challenge ahead.There is no question of nervousness or tension. We have to stay cool and be prepared for any contingency.We have done everything to make sure it succeeds. The spacecraft's propulsion system will play a major role during its entry to Mars. For this purpose we have tested the 440N liquid apogee motor for prolonged periods under a simulated environment and it performed flawlessly. But, then it has to restart in a real Martian environment on Wednesday. This will be a major challenge. To check on the state of this engine we will fire it for a mere four seconds at 2.30pm on Monday. If this is successful our team will have a high level of confidence about the orbit insertion. The spacecraft and its five payloads are in good health and checked regularly.Cops look at miniature rocket displayed at Jawaharlal Nehru planetarium during the inauguration of the 'Indian march to Mars', a festival in Bangalore. (TOI photo)Then we will be activating Plan B, which means firing only the eight thrusters of the spacecraft. For the Mars capture, the speed of the spacecraft has to come down from 22.1km per second to 4.4km per second in relation to Mars.The implementation of Plan B will result in a new and larger orbit as the eight thrusters will fire for a longer period of time. I will not be disappointed because it is possible some new science may come out of it. Let's just wait and watch. Basically, our mission is to demonstrate that we have the capability to capture the Martian orbit and once this happens on Wednesday we can declare we have been successful. We will be the first Asian nation to have reached Mars in the first shot itself.The rocket was already ready -the Polar Satellite Launch Vehicle -so that saved both money and time. Also, some of the spacecraft's sub-systems were similar to those used by other spacecraft. These were some key factors that contributed to making it an inexpensive mission. Also, labour costs are low in India. As for the fast-tracking, all I can say is our team of young, dedicated scientists slogged almost 24x7 to achieve it.There is a lot of contact between scientists of the two space agencies. Nasa's three ground stations at Goldstone in California, Madrid in Spain and Canberra in Australia have backed our mission and will monitor our orbit insertion. Since there will be complementary data from the two missions, scientists from both countries will collaborate to evaluate the information.The entire nation has been with us on this mission and its success will make every Indian proud. It will also help inspire the younger generation take up science, technology, math and engineering.