Isro to wait 14 more days for Pragyaan, Vikram signals

Scientists are hoping that as temperatures rise on the Moon, the possibility of revival will also go up.

The Indian Space Research Organisation will continue attempts to revive Vikram lander and Pragyaan rover till the next lunar sunset on October 6, scientists at the space agency said on Saturday, a day after the Sun rose on the lunar surface prompting ambitious efforts to kickstart a “bonus” phase of the Chandrayaan-3 mission.

On August 31, Indian Space Research Organisation (ISRO) released an image of Chandrayaan-3 Vikram Lander clicked around 11 am IST from about 15 m through a Pragyan rover's navigation camera, hours after the release of its first image, which shows the lander resting on the moon's surface on Wednesday. (ISRO Twitter)

There is no certainty as to when contact with the instruments will be re-established, Isro chairman S Somanath said.

“We don’t know when it will wake up. It could be tomorrow, or it could also be on the final day of the lunar day. But we are trying. It will be a great achievement if the lander and rover wake up,” Somanath said.

There is a possibility that the lander and rover will remain unresponsive after spending a lunar day – 14 Earth days – in complete darkness and temperatures as low as -200 to -250 degrees Celsius which are punishing for the batteries that store power for the devices.

But, the scientists are hopeful that as the lunar day progresses and the temperatures on the Moon’s surface rise, the possibility of a revival will also increase.

Earlier, Somanath had explained that while the rover has been tested to survive the low temperatures, the lander Vikram has not.

“Rover has been fully tested. But a lot of the design is similar for Pragyan and Vikram. This means that the tests that worked for Pragyan should also work for Vikram,” he told HT.

On schedule, Isro started the attempts for revival of lander and rover of India’s third lunar spacecraft on Friday, when the Sun’s elevation was deemed enough to repower the instruments that were put to sleep in preparation of the lunar night some 14 days ago.

Senior officials said that before the equipment was put to sleep, the batteries were left fully charged and the solar panels were oriented in a way that it receives light as soon as the Sun rises. The receiver was also kept on, so that if the instruments are able to brave the low temperatures they can be revived and begin additional experiments for another 14 days.

In a best-case scenario, when the commands are fed into the lander and the rover to bring the systems back to life, the rover will start moving around the lunar surface again and the equipment on-board the lander will also repeat the process of collecting data.

Teams at ISRO Telemetry, Tracking and Command Network (ISTRAC) started feeding commands to revive the instruments. If the machines respond upon recharging, the mission will have an extended life and scientists will be able to bag more samples.

In a historic feat on August 23, India’s space agency successfully landed near the lunar south pole.