Temperature that a satellite is subjected to in lower Thermosphere

[bradyle]

Hi,

I am designing a satellite for orbit in the lower thermosphere between 320km and 90Km. I am having trouble finding the temperatures that the satellite will reach. I know that while the gases in the atmosphere are in the region of 1000K but because of the near vacuum state there is nearly no convection, and so the main form of heat transfer is radiation. But what temperature the radiation will cause I can't find anywhere. Heat transfer was never my strong point, and we completely skipped radiation so i'm just at a bit of a loss trying to work this out so if anyone could help it would be greatly appreciated!!


Lorraine

 

[IRstuff]

> Seems to me that you should be more concerned about frictional heating
> Radiation from what? If the air is as thin as you think, the emissivity will be near zero. In any case, the governing relationship is always heat balance, i.e., heat input = heat output.

TTFN
faq731-376

 

[JamesGarry]

Lorraine,

You are correct to be concerned about heat input into the craft, but most of the heating will still be in the form of solar radiation. That can be taken care of by MLI as usual, and the odd SSM to allow for cooled areas.

You may still, depending on payload, struggle to dissipate enough heat. But heat pipes are old well-tested tech, and unless you've a surprise in the design (like a kW or two of RTG) than I see no problems.

Heed IRstuff: rho.v^3 is significant. Maybe you want to maximize on-orbit lifetime. Maybe you don't. If you do, you end up with a spear with tail fins, if not, you can design anything you want.

Red Core Consulting ltd.

http://www.redcore.ca