After a pioneering two-week mission, Indian robotic explorers are asleep in the extreme darkness of the Moon’s south pole region. Whether they will wake up when the sun shines on them at the end of this lunar night depends mostly on luck.
Temperatures near the poles of the moon It could fall to -424°F (-253°C or 20 K). However, neither the Chandrayaan-3 lander, Vikram, nor its rover, Pragyan, were able to make a flight. Historic decline on August 23 – equipped with heaters common on lunar missions.
These heaters, called radioisotope heating units (RHUs), work by passively radiating heat to keep instruments aboard the spacecraft at sustainable operating temperatures. Most commonly, RHUs are used in space The missions convert heat generated from natural decay into radioactive copies of plutonium Or polonium into electrical energy. This process eventually heats up the spacecraft’s hardware, though it’s mostly enough to help it survive extremely cold temperatures.
But without these energy systems, survival would be impossible Chandrayaan-3The robotic duo was left to chance.
Related: The Chandrayaan-3 rover and lander are in sleep mode but may wake up later this month
Weigh the opportunities
RHUs have been used on lunar landing missions since the 1970s.
Lunokhod 1, which was the first successful lunar module to cover more than 10 kilometers (6 miles) in just 10 months, powered itself using solar cells mounted on a large cover. During the nights the moonClose this lid to stay warm until the next sunrise using the energy provided by the polonium-210 radioisotope heater.
The Chinese Chang’e-3 lander and rover, which landed not far from the site of Lunokhod 1 in a large crater in the northwestern part of the moon in 2013, had similar mechanisms on board to protect them from the bitter lunar nights. The Yutu spacecraft survived the first night, but only permanently She lost her ability to move After the second. However, over the past four years, its six-wheeled successor called Yutu-2 has awakened As expected Every lunar day.
ISRO has not publicly discussed why similar isotope heaters were not installed aboard Chandrayaan-3’s Vikram-3 lander and Pragyan rover – however, the robotic duo is working great It achieved its scientific goals A region of the moon has become a hotspot for space exploration, thanks to what appears to contain reservoirs of frozen water. In fact, he was the first to ever successfully land there.
The lander even surpassed its mission objectives when it managed to “jump” onto the lunar surface, flinging itself upwards about 16 inches (40 cm) and slightly closer to its companion Pragyan, which had already been put to rest at that point. .
As for preparing the robotic duo for the first lunar night, the batteries on board the Chandrayaan 3 spacecraft were fully charged before it entered sleep mode, the Indian Space Research Organization, the Indian space agency managing this mission, said in a report. mail On X (formerly Twitter).
“After the sun goes down, the electricity goes out,” Arun Sinha, a former senior scientist at ISRO, told Space.com before the launch of Chandrayaan-3. “However, there are small opportunities to charge the battery more efficiently. If this is good, there may be another 14 days available.”
“Otherwise, she will remain there forever as India’s ambassador to the moon,” ISRO said on September 2 in a press conference. mail On X.