Explained: What Happens If Chandrayaan-3 Rover, Lander Don't Wake Up

The Indian Space Research Organisation (ISRO) has been trying to restore communication with Chandrayaan-3's Vikram lander and Pragyan rover after the two were put to sleep earlier this month.

ISRO, on September 2, announced in a post on X ( formerly Twitter) that the Pragyan rover had completed all its assignment on the Moon and was now “parked safely 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 oriented to receive the light at the next sunrise expected on September 22, 2023. The receiver is kept on,” the space agency said.

The Vikram lander was also turned off after it successfully performed a short “hop” and “exceeded its mission objectives”.

The two modules were put in sleep mode for the lunar night, which is equal to around 14 days on Earth.

What happens if Chandrayaan-3 Rover, Lander don't wake up?

At the time of putting the lander and rover to sleep, the ISRO had said that if the two don't wake up, they will “forever stay there as India's lunar ambassador”.

“Hoping for a successful awakening for another set of assignments! Else, it will forever stay there as India's lunar ambassador,” wrote the space agency.

On September 22, when the lunar sunrise was expected, the ISRO shared it tried to establish contact with the rover and lander, but in vain.

“Efforts have been made to establish communication with the Vikram lander and Pragyan rover to ascertain their wake-up condition.  As of now, no signals have been received from them. Efforts to establish contact will continue,” the ISRO said in a post on X.

Experts are hoping that the rover and lander might wake up with the crack of dawn citing examples of China's lunar lander Chang'e-4 and rover Yutu-2 that had started operating again after surviving their first lunar night in 2019. 

However, former ISRO Chairman AS Kiran Kumar told BBC that it is not necessary that the Chandrayaan-3's lander and rover wake up as temperature plummets to as low as -200 to -250 degree Celsius during night on the Moon and batteries are not designed to be stored or operate at such extreme temperatures.

Former ISRO scientist Tapan Mishra told the news agency ANI that the Vikram lander and Pragyan rover were originally designed to operate for only 14 days.

He said if they survive the first lunar night then they will be able to make it through more nights. “If it survives one lunar night, I'm sure it will survive many more lunar nights and it may probably operate from 6 months to one year. That will be a great thing,” Mr Mishra said.