ISRO puts Chandrayaan-3 rover in sleep mode to survive lunar night
As the lunar day draws to a close, ISRO has decided to put its Chandrayaan-3 rover Pragyan in sleep mode to conserve its battery and protect it from the extreme cold of the lunar night. The rover, which has completed its assigned tasks, is now parked safely and has transmitted the data collected by its payloads to the lander, which in turn relays it to Earth.
Lunar Night
ISRO announced this on Saturday through a series of tweets, expressing hope that the rover would wake up again after the lunar night, which lasts for about 14 Earth days. The lander and the rover, which landed on the Moon on August 23, were designed to operate for only one lunar day, as their electronics are not expected to survive temperatures below -120 degrees Celsius during the night.
Chandrayaan-3 Mission:
— ISRO (@isro) September 2, 2023
The Rover completed its assignments.
It is now safely parked and set into Sleep mode.
APXS and LIBS payloads are turned off.
Data from these payloads is transmitted to the Earth via the Lander.
Currently, the battery is fully charged.
The solar panel is…
However, ISRO chairman S Somanath had earlier hinted that the space agency would try to extend their life by putting them in a low-power mode. “We are going to start the process of making them (the lander and the rover) sleep in the next couple of days so that they can withstand the night,” he said after the successful launch of the Aditya-L1 solar mission on Saturday morning.
By evening, ISRO had already initiated the process. “Currently, the battery (on the rover) is fully charged. The solar panel is oriented to receive the light at the next sunrise expected on September 22, 2023. The receiver is kept on,” ISRO said.
An ISRO scientist explained that it was possible but not certain that the payloads would revive after the night. “We are trying to keep the receiver on the lander switched on and try to maintain the battery at an optimum temperature. Whether the systems wake up after the night will depend on whether the battery lasts throughout this period,” he said.
He compared it to putting a phone on power saving mode till a charging cord is available. “The charging cord for the lander and rover will be sunrise at the end of the lunar night,” he said.
ISRO also tweeted that it was hoping for a successful awakening for another set of assignments. “Else, it will forever stay there as India’s lunar ambassador,” it said.
Hibernation mode
The lander and rover are being planned to be put on hibernation a couple of days before the end of the lunar day, which is around September 6. Somanath also said that the rover had so far traveled 100 meters on the lunar surface.
The four instruments onboard the lander and two on the rover have been sending back data continuously since their landing. ISRO has already shared some of the data collected by these instruments with the public.
The space agency recently also launched its first sun observatory mission called Aditya-L1. The mission successfully lifted off from the Sathish Dhawan Space Centre SHAR in Sriharikota on September 2, 2023. The mission aims to study the Sun and its influence on the space environment around the Earth and other planets. The spacecraft is equipped with seven payloads, designed to study various layers of the Sun—ranging from its photosphere to the outer corona.
As per the latest update, the satellite is healthy and operating nominally. The first Earth-bound maneuver (EBN#1) was performed successfully while the next maneuver (EBN#2) is scheduled for September 5, 2023.