The sun is setting on India’s first attempted lunar landing. As night fell over the lunar south pole on September 20, scientists’ hopes that the solar-powered Vikram lander would contact Earth before the end of one lunar day have been dashed.
Officials at the Indian space agency ISRO reportedly believe that the Vikram lander died on impact with the lunar surface on September 6. The probe lost contact shortly before it was meant to touch down near the moon’s south pole (SN: 9/6/19), according to the Times of India.
Still, there was hope that Vikram or its onboard rover would perk up and reestablish contact. ISRO spent two weeks — the equivalent of one lunar day — trying to communicate with Vikram. The lander and its rover, Pragyan, were designed to last one lunar day before the lack of sunlight and cold temperatures shut them down.
ISRO said that its Chandrayaan 2 orbiter took pictures on September 10 showing the lander lying flat or tilted on its side. Those images, however, were not publicly released.
NASA’s Lunar Reconnaissance Orbiter also flew over the landing site on September 17. But “lunar local time was near dusk; large shadows covered much of the area,” the space agency said in an e-mail. “The exact location of the lander was not known, so the lander may not be in the camera field of view.” NASA said that it would search again on October 14, when the sun is higher in the lunar sky.
After the sun completely sets on Vikram’s landing site, temperatures there will drop to about –180° Celsius for another two weeks. The solar-powered lander’s electronics are not expected to survive the frigid night.
ISRO has yet to put out an official statement. But the Times of India reported on September 20 that the team analyzing the mission’s failure believes that it was caused by an error in the spacecraft’s automatic landing program. The newspaper quoted an unnamed scientist as saying that the lander may have started spinning on its way to the lunar surface so that thrusters meant to slow the descent instead accelerated it.