Why did all my panels suddenly explode?

[Loren Pechtel]

Mining/science ship on Minmus.  I probably had too many radiators as this was my first try at mining.  (Please, daylight-only drills!!!  The battery pack I need is insane!)  Two of the radiators were quite in the way of EVA operations so I retracted them to go get a surface sample.  My scientist was back on board, I ordered both to deploy, they are coming out and suddenly boom!  Every radiator and solar panel is lying in shards around the rocket.  While my tanks weren't full I had enough dV to make orbit anyway and that landing had already completed my mission so I can at least salvage the pile of science that's on board.

All I can think of is the radiators hit each other (they did overlap but it hadn't caused any trouble before, I had even boosted  many times with the panels deployed) but why would that destroy everything sticking out from the rocket??

[HebaruSan]

Anytime I lose a part, I press F3 to see the mission log, which should contain a message explaining exactly what happened to each part. Since you said you retracted two radiators, my guess is that the craft overheated while your heat dissipation capacity was reduced, and the solar panels are usually the first to go when that happens.

[Loren Pechtel]

19 minutes ago, HebaruSan said:

Anytime I lose a part, I press F3 to see the mission log, which should contain a message explaining exactly what happened to each part. Since you said you retracted two radiators, my guess is that the craft overheated while your heat dissipation capacity was reduced, and the solar panels are usually the first to go when that happens.

I didn't think of F3.  It definitely wasn't an overheat--I had just landed, I didn't have a drill in operation.  There was no source of heat.

[Snark]

+1 to hitting F3, it's probably the most reliable source of useful information about what happened.

1 hour ago, Loren Pechtel said:

It definitely wasn't an overheat--I had just landed, I didn't have a drill in operation.

By the way, be aware that radiators will never explode due to overheating; they're self-limiting.

Well, okay, if something else external is making them hot, like going through reentry or flying really close to the sun, then they can blow up the same as any other part.  However, they will never drain heat from other parts so much that the radiator explodes.  They have a built-in safety limiter that will cause them to stop drawing heat when they get over a certain percentage of their max temperature rating.

So the symptom of an overheating ship that has active radiators wouldn't be the radiators exploding, it would be other stuff exploding when the radiators stop pulling heat when they get too hot.  So basically the radiators would be the last thing to go.

Doesn't actually help answer your "what the heck happened" question, just something to be aware of.