Chandrayaan-2 continues to orbit the Moon; But what went wrong with the Vikram lander?


India is keen on exploring space and even though it’s a developing economy with a host of other challenges, it has managed to pull-off marvellous feats like discovering water on the moon and making satellite launches economical. With the Chandrayaan-2, the country was just 500 metres away from entering an elite space club. Unfortunately, the mission was a partial failure. What exactly went wrong with the landing module and what’s next for ISRO?

Landing on the Moon is the toughest of all. Only three countries have successfully landed on the Moon’s surface — the US, Russia, and China. These missions cost billions of dollars, and that’s where India maintains its edge. The Chandrayaan-1 mission was considered to be a success, but it only orbited the moon. This prompted ISRO (Indian Space Research Organisation) to work on a successor that could soft-land on the Moon’s surface.

Chandrayaan-2 lifted-off from Sriharikota on July 22 onboard a GSLV-III (Geosynchronous Satellite Launch Vehicle) rocket, ISRO’s most advanced launch vehicle. The mission consisted of three components — orbiter, lander (Vikram), and rover (Pragyan). According to plan, the orbiter is released from the GSLV-III rocket and makes its way towards the Moon. After a 54 day journey, it releases the Vikram lander and continues a polar orbit around the heavenly body. The idea was to soft-land Vikram on the Moon’s surface, release Pragyan, and explore the South Pole region.

Vikram did land, but it wasn’t soft enough

  • The Chandrayaan-2 weighed 3.8 tons and was capable of carrying 14 scientific experiments. The orbiter is also responsible for imaging the Moon’s surface and mapping corresponding areas. The lander itself weighed 1,471 kgs and could resist small-scale earthquakes. Lastly, the rover weighed 27 kgs and was equipped with cameras and instruments to analyse the surface rocks.
  • On September 6, everything happened as planned until the lander was 2.1 km above the surface. Then, it suddenly lost communication with ISRO and mission control couldn’t establish a new link. Though, it was able to see that the lander had gone off-course and wouldn’t land at its designated spot. This is exactly why finding wreckage, later on, became a hassle.
  • In the beginning, there were hopes that the spacecraft could’ve landed successfully and there’s just an issue with the communication array. After multiple attempts, hopes of finding an intact module on the surface was near to zero.
  • Jitendra Singh, minister of state for the Department of Space, said that the Vikram lander “hard landed” on the moon because of a problem with the lander’s braking thrusters. “The first phase of descent was performed nominally from an altitude of 30 km to 7.4 km above the Moon’s surface,” he said in a written note to the Parliament. The lander slowed from 1,683 meters per second to 146 meters per second during that time.
  • “During the second phase of descent, the reduction in velocity was more than the designed value,” he added. “Due to this deviation, the initial conditions at the start of the fine braking phase were beyond the designed parameters.” Hence Vikram hard-landed on the surface, within 500 metres of the designated landing spot.
  • ISRO acknowledged the lander likely hit the lunar surface at a high velocity, “beyond its survivability.”

Why did it take so much time to find the crash debris?

NASA was able to locate the wreckage in the first week of December. However, ISRO claims they had found the debris long back and the same was declared previously on their website. However, no detailed pictures or evidence was attached.

  • When the Vikram lander crashed, only two spacecraft were orbiting the Moon — NASA’s Lunar Reconnaissance Orbiter (LRO) and ISRO’s orbiter.
  • ISRO didn’t share any mission details with NASA, leaving the latter to go through billions of pixels of images to find the wreckage. Noah Petro, the project scientist for LRO, told, “Until we know more details about where Vikram is, it’s going to be very hard for us to find it.”
  • Vikram didn’t land at the designated spot. Hence the surrounding regions had to be processed, taking more time. The LRO made its first pass over the region on September 17 and all corresponding data was released to the public on September 26.
  • Amateurs around the world swift through this data dump, trying to find a few pixels that could clear the air and reveal the wreckage. Shanmuga Subramanian was officially credited by NASA for finding the crash debris. The Chennai-based technologist discovered debris about 750 m from the main crash site of the lander. 
  • In an e-mailed response to the Economic Times, Subramanian said he was hooked to the images released by NASA and kept scanning it for days on end. “Initially there were a lot of false positives I got corrected by Twitterati and one of the tweets led me to a Reddit forum where they had the exact intended landing location and the path of Vikram..”
  • Later, the LRO made a couple of more passes over the region and better lighting conditions on the surface ensured better photographic data. After stacking and comparing pictures from various passes, it was established that the wreckage was found.

How did the world respond to India’s unsuccessful attempt?

  • Tom Soderstrom, chief innovation and technology officer at NASA’s Jet Propulsion Laboratory said failures are a part of space exploration. And, he’s correct. The US and Russia have spent billions on unsuccessful attempts, ultimately learning and improvising.
  • Soderstrom told IANS that landing a rover is a very difficult thing. “So we get super nervous every single time. We never know if it’s going to work there, one little thing goes wrong and the whole thing is expected to fail,” he added.
  • The loss of the Vikram lander took place less than five months after Israel’s first lunar lander, Beresheet also crashed during landing. Authorities attributed a computer glitch during the lander’s descent that led it to crash.
  • Lastly, according to Soderstrom, the key here is for “us to share all that learning so that more people can participate in the endeavour to reach the next frontier in space”. 

Soderstrom has a very good point. Space exploration shouldn’t be about which country does it first. It’s a completely new frontier that demands the best of humanity. It is a showcase of human intelligence and curiosity. Collective efforts reap the best result.

Today, the International Space Station (ISS) is a collective effort of numerous countries. Each trying to contribute as much as they can. Imagine, even stark rivals like the US and Russia have made peace and western astronauts are carried to the ISS in a Soyuz rocket.

For India, the loss of the Vikram lander is a minor hiccup. The country intends to launch a manned mission to space via Gaganyaan in the coming years and reports are suggesting Chandrayaan-3 will lift off by the end of November.