‘15 mins of terror’, says ISRO chief on Chandrayaan 2 moon landing

At 1:40 am on Saturday, scientists will initiate complex manoeuvres lasting 15 minutes that, if successful, will make India the first to land near the South Pole of Moon.

Indian Space Research Organization (ISRO) scientists will be glued to their consoles tracking telemetry parameters at the Missions Operation Complex in Bengaluru, as Chandrayaan 2 attempts a soft landing near the South Pole of the moon on September 7. Since the takeoff on July 22, the team of scientists has been working upto 16 hours a day: calculating the orbit, performing simulations, and planning complex orbital manoeuvres.

The powered descent, which India will attempt for the first time, was described as “fifteen minutes of terror” by the ISRO chairperson K Sivan. “It will be a terrifying moment for us. Everybody’s eyes would be glued to their consoles. The telemetry parameters will keep telling us that we are going in the right direction, but at the same time, there will be a lot of anxiety about what will happen in the next moment,” ISRO chairperson K Sivan had said, describing the most challenging phase of the mission after Chandrayaan 2 had entered in a lunar orbit on August 20.

Watch| Chandrayaan 2 about to create history: The journey so far

 

To ensure that the ₹978 crore mission is a success, scientists made last minute changes to the design of the lander in mid-2018, as suggested by the group of eminent scientists, and even conducted a development flight of the GSLV Mark III vehicle in November 2018, which would take the heavier payload to space. On July 15, when the mission had to be aborted at the eleventh hour because of a technical snag, many did not leave the launch site at Sriharikota for over 24 hours: the problem was detected; the fuel tank of the launch vehicle emptied out; and the problem was fixed.

Successful landing

“Landing on the moon is a complex mission. India will attempt to land near the South Pole for which the orbit around the moon has to be precise, making the mission more complex. A success will show the world the technical capability of India,” said Mylswamy Annadurai, former head of the UR Rao Satellite Centre and the project director of Chandrayaan 1.

The success of Chandrayaan 2 will show that the ISRO is capable of putting a spacecraft in a polar orbit around the moon, landing on the lunar surface, and studying the moon using the indigenously developed lander and rover.

It would also be a “giant step” for India and its space programme. It would make India the fourth country to land on the moon — the first to do so near the South Pole. The landing of the Vikram lander, which is scheduled at 01:55 am, is not the end of the 48-day journey to the moon. A successful landing will ensure that the mission is able to return valuable scientific data to Earth.

So far, all the soft landings on the moon have happened in the region between the lunar equator and 30 to 40 degrees north or south of it. Chandrayaan 2 will land 70 degrees south of the equator. And, even then only 45% of all the soft landings attempted were successful. In contrast, Chandrayaan 1 was an impact mission -- its lander was expected to crash.

What’s more, the technology is also completely indigenously developed by ISRO scientists.

“When the Chandrayaan 1 mission was being planned, we did not have enough resources to make all the high-tech scientific equipment. That’s why we enquired about others looking to send experiments to the moon and collaborated for the mission. For Chandrayaan 2, everything was developed by us,” said a scientist who had worked on the Chandrayaan 1 team, on condition of anonymity.

India’s second mission to moon was approved by the cabinet in September 2008, just before the launch of Chandrayaan 1. However, Russian space agency Roscosmos that was to provide the lander for the mission withdrew from the project. This is when India decided to develop its own lander.

“It gave India the opportunity to show that partner or no partner we are capable of developing all the technologies indigenously,” said Ajay Lele, Senior Fellow working with space security and strategic technologies at the Institute for Defence Studies and Analyses.

“This also lays the groundwork for future collaborations with other spacefaring countries for inter-planetary missions,” he said.

The right site

It is estimated that the craters in the permanently shadowed areas of the South Pole hold most of the water ice of the lunar surface — 100 million tonnes. That’s not a lot. On Earth, Greenland lost 125 times this ice cover in one day when it experienced the largest single-day melt this August.

“But the presence of water is important for future missions to the moon as it will allow for the astronauts to stay on the lunar surface for more than just a few hours,” said Annadurai.

The data collected by the Chandrayaan 2 will be important for the upcoming manned Artemis mission to the lunar South Pole in 2024 that has been announced by NASA.

“If you ask me what will the benefit of the mission tomorrow, I won’t be able to tell you. But this is the right time to invest in such scientific missions to reap the benefits in the future. And, India is doing just that,” said Lele.

And, what future benefits can we hope to reap? “Minerals on the Earth are fast depleting and moon can be looked at as a future stockpile, especially when it comes to Helium 3. Helium 3 is rare on Earth is found abundantly on moon. Theoretically, it can be used as fuel in nuclear reactors instead of plutonium etc and just one aircraft of Helium 3 would be enough to solve the power crisis of the world for a decade,” he said.