Chandrayaan-3 enters critical phase: ISRO chief
Somanath Says spacecraft moving
into 100-km circular orbit is crucial
Sriharikota: The Chandrayaan-3 spacecraft inched closer to its soft landing on the Moon as it successfully underwent a planned orbit reduction manoeuvre lowering its lunar orbit on Sunday.
However, the most critical phase of Chandrayaan-3 will begin when the spacecraft starts moving closer to the Moon from the 100 km circular orbit, according to ISRO chief S Somanath.
The orbit determination process of Chandrayaan-3 will be planned between August 9 and 17 to place the spacecraft in a 100-km circular orbit, Somanath said on Monday, adding that India's third lunar mission is in good health.
Launched on July 14 by the Launch Vehicle Mark-3 rocket, Chandrayaan-3 spacecraft is now placed in a 170 km by 4,313 km elliptical orbit around the moon.
The next critical phase will see a series of manoeuvres which will move it closer to the lunar surface.
The Vikram lander is expected to descend on the moon on August 23. "Up to 100 km we do not see any difficulty. The issues are only in estimation of the position of the lander accurately from earth. This measurement is a very critical measurement, we call it the orbit determination process.
If it is correct, the rest of the process can be done," Somanath said.
"We are able to bring it down very correctly this time. The orbit changes are happening as planned. There is no deviation. So, it shows excellent results, and we are hoping that all will be fine," the ISRO chief said. He said the experience from Chandrayaan-2, the 2019 mission that was a partial success, was proving to be very useful as the space agency attempted to land a spacecraft on moon. "The Chandrayaan-2 experience will be of great help. We went through in great detail on what possibly went wrong. We re-constructed the scenario and made a lot of modifications to Chandrayaan-3," Somanath said.
He said images of the moon from Chandrayaan-2 mission were used in Chandrayaan-3 for its better positioning and increasing the landing area measurements.
"We have gathered more intelligence to handle contingencies and failure.
We went through an extensive testing programme to validate all of this," Somanath said.