3 ms·

This is fascinating, but I do have an off topic question: why does a robotic arm need a thermal blanket?

zdkl 5y ago
Probably to mitigate material stress due to temperature swings from alternating exposure to sunlight.
bleuarff 5y ago
I'm no expert, but there's probably some electronics in that arm whose operating temperature range is a lot higher than the temperature of space.
- bagels 5y ago
  Typically the electronics are trying to shed heat, not retain it since there is no air convection.
  - frederikvs 5y ago
    While there is no air convection, there is a lot of heat loss via radiation. Of course, if there's a CPU in there that's drawing lots of power (e.g. image processing), it will have to shed that heat. But if there's only some electronics in there that don't eat up too much power, there's a good chance they'll use the thermal blanket (and even heaters) to keep them warm. I don't have the details on the Canadarm, but I can tell you that a lot of electronics on satellites use thermal blankets and heating elements to keep warm.
StreamBright 5y ago
Thermodynamics in space are crazy. You usually either overcool or overheat (depending on facing the Sun or facing deep space) there is no normal operation. Thermal insulation is a must.
qbasic_forever 5y ago
Aw come on let's not shame the poor robot arm. Space is a cold and lonely place--I'd want a blanket too. :)
colechristensen 5y ago
The only way to lose heat in space is by radiating away infrared. If you have motors that generate heat you have to have a solution for getting rid of that heat. There’s also the sun blasting you with more than a kilowatt per square meter which goes from 100% to 0% in 90 minutes in low earth orbit. One way to mitigate this is to add mass, but making a long splindly arm considerably heavier is problematic. Imagine all the things you would need to do if you were running a marathon on a course that alternated half a dozen times between a blizzard and a death valley heat wave... you would have to work with many many constraints and come up with a solution that worked for opposite extremes while not interfering with the thing you’re actually trying to do.

zdkl 5y ago

Probably to mitigate material stress due to temperature swings from alternating exposure to sunlight.

I'm no expert, but there's probably some electronics in that arm whose operating temperature range is a lot higher than the temperature of space.

bagels 5y ago
Typically the electronics are trying to shed heat, not retain it since there is no air convection.
- frederikvs 5y ago
  While there is no air convection, there is a lot of heat loss via radiation. Of course, if there's a CPU in there that's drawing lots of power (e.g. image processing), it will have to shed that heat. But if there's only some electronics in there that don't eat up too much power, there's a good chance they'll use the thermal blanket (and even heaters) to keep them warm. I don't have the details on the Canadarm, but I can tell you that a lot of electronics on satellites use thermal blankets and heating elements to keep warm.

StreamBright 5y ago

Thermodynamics in space are crazy. You usually either overcool or overheat (depending on facing the Sun or facing deep space) there is no normal operation. Thermal insulation is a must.

qbasic_forever 5y ago

Aw come on let's not shame the poor robot arm. Space is a cold and lonely place--I'd want a blanket too. :)

colechristensen 5y ago

The only way to lose heat in space is by radiating away infrared. If you have motors that generate heat you have to have a solution for getting rid of that heat. There’s also the sun blasting you with more than a kilowatt per square meter which goes from 100% to 0% in 90 minutes in low earth orbit. One way to mitigate this is to add mass, but making a long splindly arm considerably heavier is problematic. Imagine all the things you would need to do if you were running a marathon on a course that alternated half a dozen times between a blizzard and a death valley heat wave... you would have to work with many many constraints and come up with a solution that worked for opposite extremes while not interfering with the thing you’re actually trying to do.