Night is slowly engulfing the lunar south pole.
ISRO has put two instruments on Pragyan into hibernation. The Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectrometer (LIBS) are now “safely parked and in sleep mode,” ISRO said on Twitter. Their batteries are fully charged.
On September 22, the first rays of sunlight will shine on the rover and lander. The solar panel is oriented to receive sunlight and the receiver remains on.
“Wishing success for another set of missions awakening! Otherwise, it will stay there forever as India’s lunar ambassador,” ISRO said in a tweet.
During moonlit nights in the Antarctic region, temperatures can drop to minus 173 degrees Celsius.
But why can’t we protect them?
One question that arises is, can the electronics on a rover or lander be protected from the lunar cold?
The answer is, yes, you can. Typically, spacecraft instruments are protected from extreme temperatures. Examples include the Mars rovers—Spirit, Opportunity, and Curiosity. Yes, Martian night, like Earth night, only lasts 12 hours, but a spacecraft as far from the sun as Voyager can survive extremely cold temperatures for years.
A paper in the International Journal of Aerospace Engineering proposes a multilayer insulator
But the main goal of the Chandrayaan-3 mission is to demonstrate a soft landing on the moon.experimenting is secondary
Typically, spacecraft have heat-generating systems such as a “radioisotope heating unit” (RHU) or a radioisotope thermoelectric generator (RTG); heat from the radioactive decay of plutonium-238 provides comfort for onboard electronics.
But these are heavy. For example, the RTG onboard the Galileo probe (1989) weighed 56 kg. When ISRO’s focus is purely on achieving a soft landing, adding weight to the lander or rover would conflict with its primary goal.
Also read: Plakia rover crawls on the moon
Scientists are working on alternative ways to keep the small rover alive at night. One suggestion is to use (lightweight) multi-layer insulation (MLI) – a curtain made of insulating material, like the vertical blinds in our house. The MLI can drop from the bottom of the lander, creating a small chamber between the lander’s legs. The rover can climb in and rest for the night.
But that’s all for later. For now, 14 days of work for the lander and rover after a successful touchdown is enough.