DB Original/ Former ISRO scientist Dr M Annadurai explains inside story of Chandrayaan-2 Moon Mission

  • The Chandrayaan-2 project was approved in 2008, but in 2013 Russia refused to deliver the lander and rover
  • Former programme director Dr. Annadurai told- Orbiter was ready for Chandrayaan-2, but it could not be kept for long and so it was used in Mangalyaan
  • According to Dr. Annadurai, preference was given to young scientists for Chandrayaan-2 so that they could devote more time to the mission
  • Rocks like the lunar surface were discovered in Tamil Nadu, they were crushed and surface like moon was created on Earth

New Delhi: The Chandrayaan-2 mission of the Indian Space Research Organisation (ISRO) is the story of fighting a difficult situation. When the Chandrayaan-2 project was approved in 2008, it was decided that Russia would provide the lander and rover for this mission. But by the time Russia refused it in 2013, ISRO had prepared the orbiter. The orbiter is the part of the vehicle that can orbit the Earth and the Moon and make a lander land on the lunar surface. Interestingly, ISRO then made some changes to the orbiter and used it in the 2013 Mangalyaan mission. In this way, live testing of the most important part of Chandrayaan-2 was done 6 years ago. Dr. M Annadurai, the project and program director of Chandrayaan-1 and Chandrayaan-2 and now retired from ISRO, told many important things in this mission in a conversation with Bhaskar App.

Orbiter made for Chandrayaan-2 could not be kept for long

Dr. Annadurai explains that for Chandrayaan-2 we had entered into an agreement with the Russian space agency Roscosmos. ISRO was responsible for making the orbiter, while Lander and Rover were to be mace by Russia. The mission was to be completed in 4 to 5 years. When Russia refused to give the lander and rover due to technical difficulties, we understood that it would take another 4 to 5 years for this mission. We had made orbiter. One challenge before us was that we could not keep it for much longer. So we made some changes to Chandrayaan-2’s orbiter and prepared it for the Mangalyaan mission. We launched this same orbiter in the Mangalyaan mission.

We had to create a moon-like atmosphere on Earth

Dr. Annadurai says that for the lander we had to make various sensors like thrusters and ultimators, orient ultimators and accelerometers. We had to make all these things anew and test them. The biggest challenge for us was to test because we had to create a moon-like atmosphere on earth. We were doing all this for the first time. We had chosen a place (Moon’s South Pole) for landing where no one has gone till today. So for the soft landing of the lander, we collected data from Chandrayaan-1 and other places. Based on this data, we created a site like the Moon’s South Pole on Earth itself.

Biggest challenge was the lander, it required 70 tonnes of soil like moon for its testing

Former project director Annadurai explains that the biggest challenge for us was to make the lander, because we had already made the orbiter and had already sent it to Mangalyaan, which was successful. So we had to do the same thing again. However, even after this, we had to build everything using indigenous technology. We needed 70 tons of soil. Salem in Tamil Nadu has rocks, which are similar to rocks on the moon. Scientists grinded those rocks to form a moon-like soil. From there, this soil was brought to ISRO Satellite Integration and Testing Establishment in Bangalore and a two-meter thick surface was made there. The lander has been landing thousands of times in the last four years on that soil.

Chandrayaan-2 was heavier, so it took 10 years

Annadurai says- payloads and instruments we made for Chandrayaan-1 were also indigenous. But, for Chandrayaan-2, we needed better payloads and instruments than before. We did not have much problem in making the rover. This mission took more than 10 years to launch due to Russia’s refusal. The Chandrayaan-2 weighed more than the Chandrayaan-1, so GSLV Mark-II was not able to carry it, so we used the GSLV Mark-III. We had earlier made PSLV and GSLV based on indigenous technology. The Chandrayaan-1 that we sent earlier was also prepared with indigenous technology. So we knew that we had to make it now. But, it was a big challenge to prepare all this on a low budget and in a short time.

Everyone wanted to be a part of mission, but the youth were preferred

Annadurai says that we had the experience of Chandrayaan-1 and Mangalyaan. It helped us a lot. The Chandrayaan-2 mission was very interesting and challenging, so everyone wanted to work and be a part of this mission. This mission required more time than other missions. Therefore, the youth were hired because they could devote more time. It was the first mission in the world, in which a vessel was to land on the moon’s south pole. So everyone worked hard to make this mission a success. Our families should also get an idea of ​​our hard work, for this, not only the director, but all the people associated with this mission used to bring their family members on Science Day, Technology Day, Mother’s Day and show their work to them.

Launching postponed four times 

The launch of Chandrayaan-2 was also postponed four times. It was first to be launched in October 2018, but was later extended to 3 January 2019 and then 31 January. It was later postponed until July 15 for other reasons. But on July 15, the mission was postponed 56 minutes before the launch due to technical flaws. It was finally launched by GSLV Mark-3 called ISRO’s Bahubali rocket at 2:43 pm on 22 July.

(Story by Priyank Dwivedi)