Chandrayaan-3 healthy, everything going as planned, say Isro officials

Chandrayaan-3 is healthy and everything is going as per the plan, officials familiar with the development at the Indian Space Research Organisation (Isro) said on Saturday, a day ahead of the second de-boosting operation of the spacecraft, scheduled on August 20.

While the initial plan was to put the lander, Vikram, in an orbit of 30kmX100km, it attained an orbit of 113kmX157km after the first de-boosting operation on Friday, the officials said.

They said that this was not particularly a cause for concern.

“The 30kmX100km orbit was under nominal conditions. Moreover, these were just estimates because the actual plan has not been revealed due to security reasons. The current position and movement of the spacecraft is being monitored continuously by our teams and everything is going as per the plan,” the official said requesting anonymity.

The official explained that initially the lander was supposed to reach an orbit where the perilune (the point at which a spacecraft in the lunar orbit is closest to the moon) would be around 30km, and the apolune (the point at which the spacecraft is furthest from the moon) would be around 100km.

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The space agency conducts de-boosting or deacceleration operation to gradually reduce the velocity of the spacecraft so that it attains a specified controlled speed before landing on the surface of the moon.

The next de-boosting maneuver is planned for Monday, which will be followed by the last round of braking procedures, before the spacecraft attempts to land on the surface of the moon on August 23 between 5.30pm and 6pm.

On Monday or Tuesday, the spacecraft will also be flipped from a horizontal orientation to a vertical orientation, the space agency said.

A follow-up mission to the 2019 Chandrayaan-2, the latest programme has three objectives —to demonstrate safe and soft landing on the lunar surface, which could not be achieved during Chandrayaan-2, to demonstrate rover abilities on the surface of the moon and to conduct in-situ scientific experiments.

Chandrayaan-3 was launched from the Satish Dhawan Space Centre in Sriharikota on July 14.

It consists of an indigenous lander module (LM), propulsion module (PM) and a rover, with an objective of developing and demonstrating new technologies required for interplanetary missions. The lander has the capability to soft land at a specified lunar site and deploy the rover, which will carry out in-situ chemical analysis of the lunar surface during the course of its mobility.

After the lander module was separated from the propulsion module, the latter will now continue its journey along the lunar orbit for at least six months.

The propulsion module has Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to study the spectral and Polari metric measurements of earth from the lunar orbit. In simpler terms, the propulsion module has started performing a spectroscopic study of the earth’s atmosphere and measure the variations in polarisation from the clouds on earth, to accumulate signatures of exoplanets that would qualify for our habitability.