Chandrayaan-3 mission: Why Chandrayaan-2 mission horribly failed?
Launched from the Satish Dhawan Space Centre in Sriharikota on Friday (July 14) at 2:35 pm, the Chandrayaan-3 is India’s third lunar mission and second attempt to make a soft landing on the Moon. The mission is expected to reach the lunar orbit a month after its launch, and its lander and rover are likely to land on the lunar surface on August 23.
The launch of Chandrayaan-3 came almost four years after the partial failure of the Chandrayaan-2, which was sent to space on July 22, 2019. The Chandrayaan-2’s lander, Vikram, and rover, Pragyaan, crashed on the Moon’s surface.
Objectives of Chandrayaan-2
The primary objectives of the Chandrayaan-2 lander were to demonstrate the ability to soft-land and operate a robotic rover on the lunar surface. The scientific goals of the orbiter are:
- to study lunar topography, mineralogy, elemental abundance, the lunar exosphere, and signatures of hydroxyl and water ice.
- to study the water ice in the south polar region and thickness of the lunar regolith on the surface.
- to map the lunar surface and help to prepare 3D maps of it.
Why did the Chandrayaan-2’s lander fail to soft-land on the Moon?
On Monday (June 10), ISRO Chairman S Somanath pointed out three mistakes that led to the hard landing of Vikram.
1. “The primary issues were, one, we had five engines which were used to give the reduction of the velocity, which is called the retardation. These engines developed higher thrust than what was expected,” Somanath told the reporters, according to a public report. He explained that the extra thrust led to the accumulation of errors, which, in turn, compromised the stability of the lander during the “camera coasting phase’’ for the soft landing.
2. This is where the second problem occurred. “All the errors got accumulated, which was on the higher side than what we had expected. The craft had to make very fast turns. When it started to turn very fast, its ability to turn was limited by the software because we never expected such high rates to come,” Somanath added.
3. The third problem emerged when the lander, despite being close to the surface, increased its velocity as the landing site was quite far away. Somanath said this partly happened because the landing spot was quite a small patch of 500 m x 500 m.
“In a nutshell, the problem in Chandrayaan-2 was that the ability to handle parameter dispersion was very limited,” he said, according to the PTI report.
