Comment by danpalmer
2 days ago
Starlink is however operating at ~500km where radiation is less of a concern, but where the lifetime of a satellite is only 2-3 years.
The unit economics of orbital GPUs suggest that we'll need to run them for much longer than that. This is actually one of the few good points of orbital data centers, normally older hardware is cycled out because it's not economic to run anymore due to power efficiency improvements, but if your power is "free" and you've already got sufficient solar power onboard for the compute, you can just keep running old compute as long as you can keep the satellite up there.
I think they last 2-3 years after they run out of argon fuel, so more like 7-8 years total. It looks like some Starlinks from Nov 2019 are still operational.
My understanding was that anything at ~500km needed readjustments every few months in order to not come down. Much less than 2-3 years.
I'd be interested to know what the average lifespan or failure rate of Starlink has been. That's good that some are still up there 6+ years later, but I know many aren't. I'm not sure how many of those ran out of fuel, had hardware failures, or were simply obsolete, but an AFR would be interesting to see.
The atmosphere is still thick enough to drag you down at 500km. You would last typically last a few years before burning up - the rate of fall is pretty low at 500km. But you do need fuel to do collision avoidance manoeuvres and for attitude control (otherwise your panels will no longer face the Sun and your antennas will not face the ground).
1 reply →
Quite helpful infographics from ULA: https://blog.ulalaunch.com/hubfs/orbital%20debris.jpeg
Jonathan McDowell keeps track of all the Starlink Sat orbits, including failures:
https://planet4589.org/space/con/star/stats.html
Or in theory, indefinitely,
https://news.ycombinator.com/item?id=16527007 ("First firing of air-breathing electric thruster (esa.int)" (2018))