Chandrayaan-2: Lander-orbiter separation today
The decision was taken after a high-level review committee meeting on Saturday. “The separation is scheduled for around 1.30pm tomorrow (Monday),” a scientist who was on the review committee told TOI.
Another scientist said that the committee decided to carry out the separation from the same orbit achieved after a 52-second manoeuvre on Sunday evening that put the module in a 119km x 127km orbit around Moon.
Talking to TOI soon after the manoeuvre, Isro chairman K Sivan said, “We wanted close to the 100 x 100 km orbit. Today, we achieved the 119 x 127km orbit. This small variation in orbit is the requirement needed for correct landing as it will bring the lander exactly over the landing site on September 7 morning. This small orbit variation is therefore there.”
He said, “Around 1pm tomorrow (Monday), Vikram lander will get separated from the orbiter to continue its downward journey to land on Moon. Vikram’s separation will be just like the “parting of a bride from her parent’s house. From tomorrow onwards, our entire focus will be on Vikram. However, another team will continue to monitor the orbiter.”
He said Monday’s separation operation would be another milestone that the scientists are confident of achieving. “The process is similar to how a satellite separates from a launch vehicle,” he said. The separation will remove the landing module — now sitting on top of the orbiter — making Vikram independent for the first time since July 22 when the integrated module was launched from Sriharikota.
“All spacecraft parameters are normal,” Isro said. Following the lander module separation on Monday, Vikram will undergo two deorbit manoeuvres as a prelude to landing in the south polar region of Moon.
On Monday, Isro will load the sequence of commands for Vikram’s separation, which will then be autonomously executed by the onboard systems. The landing module and the orbiter are held together by clamps with two bolts— two halves of a metal flat spring are used to hold them together — and these bolts will be sheared to release Vikram.
An explosive bolt like the ones used for ejection of the pilot’s seat in fighter planes does the job, a scientist explained. “This system has high strength and stiffness when clamped and releases in less than 50 milliseconds once the command is given,” the scientist said.
Once the separation is successful, India will only be less than a week away from Moon landing, which is scheduled for September 7. A successful landing will make it the fourth country after Russia, the US and China to have achieved such a feat.
References
- ^ Chandrayaan-2 (timesofindia.indiatimes.com)
from Times of India https://ift.tt/2ZyKwuI
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