Sun rises over Chandrayaan-3's landing site, ISRO hopes for Vikram's revival on Sept 22

ISRO scientists must have their fingers crossed as the Sun has started to rise over the Chandrayaan-3 mission's landing site 'Shivshakti' near the Moon's South Pole. It was estimated that the sunrise would begin around the landing site early on Wednesday which would entail an update on the mission from ISRO. 

The Vikram lander of the mission touched down about 600 kilometres from the Moon’s South Pole on August 23 and functioned on solar power for 14 Earth days or one lunar day. The Lunar Day ended around September 5-6 which reduced the power generated by Vikram's solar panels as well as that of the six-wheeled Pragyan rover which also works on solar power. 

On September 4, ISRO announced that Vikram's instruments- ChaSTE, RAMBHA-LP and ILSA - have been turned off until the Sun rises again. "Vikram will fall asleep next to Pragyan once the solar power is depleted and the battery is drained. Hoping for their awakening, around September 22, 2023," ISRO said in a statement. 

Chandrayaan-3 Mission:
Vikram Lander is set into sleep mode around 08:00 Hrs. IST today.

Prior to that, in-situ experiments by ChaSTE, RAMBHA-LP and ILSA payloads are performed at the new location. The data collected is received at the Earth.
Payloads are now switched off.… pic.twitter.com/vwOWLcbm6P

— ISRO (@isro) September 4, 2023

ISRO hopes for Chandrayaan-3's revival

The future of the Chandrayaan-3 mission is uncertain because the Vikram lander and Pragyan rover have been enduring temperatures as low as at least -200°C. ISRO will attempt to revive the payload to continue the mission beyond its expected timeline. It is worth noting, however, that the temperature during the daytime on the Moon needs to go above a specific threshold to revive the instruments. 

Technically speaking, the Sun does not 'rise' or 'set' near the Lunar Poles as it is never more than 1.5° above or below the horizon, says NASA. Owing to the Moon's position and tilt, the sunlight always skims the horizon both on the North and South Poles which is why some craters never receive any sunlight and these craters make up the permanently shadowed regions. 

Vikram landed on a highland which receives relatively higher amounts of sunlight to power it throughout its lifespan. The lander's solar panels can generate up to 738W of power while the rover's panel can generate 50W of power. The Chandrayaan-3 mission launched from the Satish Dhawan Space Center in Sriharikota aboard the LVM3 rocket on July 14 and the successful landing made India the first nation to touch down on the Lunar South Pole. India also became the fourth nation to safely land on the Moon after the US, USSR and China.