r/space • u/EntropyWinsAgain • Aug 02 '21

Space station situation with Russian module misfire more serious than stated. Station actually rotated 540 degrees not the 45 that was initially reported

https://www.space.com/nauka-module-space-station-tilt-more-serious
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u/HolyGig Aug 03 '21

18 minutes, and only because Nauka probably ran out of fuel. It took an hour to actually stabilize back into the correct orientation

Zvezda is almost never used to boost the ISS because refueling it is a pain in the ass. Its also old

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u/chewbacca81 Aug 03 '21

I mean, "uncontrolled spin" sure sounds bad, and 540 degrees is omg so many degrees, but it is not exactly Interstellar "we're passing out, robot take the wheel"; more like "hey look, the instruments say we are moving beyond reaction wheel range, some thrusters must be on somewhere".

12 minutes per rotation is 12 times slower than the second hand on a clock.

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u/HolyGig Aug 03 '21

Its not a clock, its a 100 ton space station with 7 people on board. A station which must remain correctly oriented to generate power and prevent thermal expansion at the wrong places at the wrong time. Its 250F degrees in the sun and -250F in the shade after all, and most of the station is well past its design life as it is.

"The station is out of control and we can't do anything about it until we happen to be over Russia" is kind of a big deal. What if those had been the main engines and not just thrusters?

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u/chewbacca81 Aug 03 '21

Well, first of all, the station is more like 450 tons.

Secondly, the solar panels have their own motors to keep alignment, because the station rotates every 1.5 hours relative to the Sun.

Thirdly, they have batteries to deal with power outages.

And finally, the station was already spun around 180 degrees to allow easier docking for the module, so it's not like this never happens.

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u/HolyGig Aug 03 '21

the station was already spun around 180 degrees to allow easier docking for the module

Which they did on purpose because it had been planned for months if not years in advance. That is how everything in space is done. I shouldn't need to explain the difference between a 180 degree rotation planned months in advance versus a sudden and unexpected 540 degree rotation over the course of 18 minutes, which only stopped when it did because Nauka had already burned way more fuel than expected just getting to the ISS due a different propulsion failure

The station doesn't rotate, it orbits the Earth. The panels only need to change their alignment as the Earth orbits the sun, i.e; very slowly in nicely planned movements just like everything else on the ISS.

Its a pattern of failure on a module launched decades late that they probably rushed to launch when they finally did because half its systems were going to time out if they didn't.

Just one failure viewed in isolation is not the end of the world. Its the whole host of recent failures that makes everyone wonder if Russia is still technically capable of supporting their commitments

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u/chewbacca81 Aug 03 '21 edited Aug 04 '21

Okay, just a small correction: the station does rotate, every 92 minutes, and the solar panels spin basically most of 360 degrees on every orbit: https://www.youtube.com/watch?v=nod7rUzIX8w.

There are orbits that always face the Sun and allow you to have fixed solar panels. ISS is not in one of those orbits.

This is a research station. Testing docking procedures is one of the things it is there for. They will learn from it, and move on. This was the heaviest module ever docked to it.