Goodnight Vikram, Goodnight Pragyan

(With apologies to Margaret Wise Brown)  As the moon goes into the gibbous waning phase and lunar night has reached Chandrayaan-3 landing site, we read that both the lander and rover have gone into sleep mode.  When they landed back on August 23, the plan was to spend a full lunar day on the mission - about 14 days here on Earth.  It has been 12 days, but both the Vikram lander and Pragyan rover have been put into "sleep mode" for the next two weeks.  

"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 post on X on Monday, Sept. 4. 

Just before it went to sleep, the lander performed a short "hop," briefly firing its thrusters to move by about 16 inches (40 centimeters), closer to the already sleeping Pragyan rover. This hop may be seen as a test for a future sample return mission that would need to launch from the moon's surface.

This is where we find out if Vikram and Pragyan have more in common with JPL missions, which typically stretch missions scheduled for short periods into much, much longer operational successes.  Things like the Ingenuity helicopter on Mars, that was originally intended for 5 flights and completed its 56th flight 10 days ago on August 25th.  Or the Mars Rover Opportunity, originally scheduled for 90 days and worked for 15 years.  The champions of that are the Voyagers - both 1 and 2 - intended for a four year mission and now in their 46th year.  

They are waiting for their next sunrise on September 22nd.  The lunar temperatures in the depth of night are pretty extreme, but in my experience, the only thing to be wondering about is their batteries.  Let me rush to say I haven't done the test of putting a circuit into a cooler at -200F for two weeks and then turning it on, but I don't even recall seeing an option on data sheets for surviving that and then being re-powered.  

That Tweet, with the photos, should be available here. 

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For those who didn't hear, SpaceX successfully launched their 62nd mission of the year Sunday night, successfully putting 21 Starlink satellites in their preliminary orbits and recovering the booster.  Originally set for around 7:25 PM, there was a cascade of delays until after 11:00 PM (ET, of course). 

Until last night, all SpaceX missions were shown on the SpaceX/launches website, like this one. This launch marked a move to X (formerly Twitter, of course), and no YouTube SpaceX coverage. Thankfully, NASASpaceflight covered it, and you can see it here.  That should start at T-30 seconds.  Unlike SpaceX's previous videos, NASASpaceflight.com starts earlier before the launch, has more interactive hosts with Q&A sessions and sticks with the coverage longer.