Chandrayaan's next crucial orbit manoeuvre by 2 pm today

The craft will be placed within the 100 km circular orbit via a series of manoeuvres

INDIA-SPACE/

The Indian Space Research Organisation (ISRO) has said Chandrayaan-3's next crucial orbit manoeuvre will happen on Wednesday between local time 1 pm and 2 pm.

The Chandrayaan-3 spacecraft will be placed within the 100 km circular orbit via a series of manoeuvres on Wednesday and August 17. After entering the moon's orbit on Saturday, the spacecraft achieved its first manoeuvre on Sunday when it successfully carried out orbit reduction by placing itself in a 170 km by 4,313 km elliptical orbit around the moon.

"The spacecraft successfully underwent a planned orbit reduction manoeuvre. The retro-firing of engines brought it closer to the moon's surface, now to 170 km x 4,313 km. The next operation to further reduce the orbit is scheduled for August 9, 2023, between 1300 and 1400 hrs IST," ISRO tweeted on Sunday.

There will be more moon-bound manoeuvres till August 17, following which the landing module, comprising the lander and rover, will break away from the propulsion module. 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 told PTI on Monday.

He added that ISRO could 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 chairman said.

The ISRO chief has also elaborated on the mission's intricacies when he said on Tuesday that the Vikram, the lander of India's third lunar mission Chandrayaan-3, will be able to make a soft-landing even if all the sensors and two of its engines do not work.

"The entire design of the lander ‘Vikram' has been made in a manner that makes sure that it would be able to handle failures," Somanath said during a talk on 'Chandrayaan-3: Bharat's Pride Space Mission', hosted by the non-profit organisation Disha Bharat. "If everything fails, if all the sensors fail, nothing works, still it (Vikram) will make a landing. That's how it has been designed -- provided that the propulsion system works well,"  Somanath said.