SimonShuttle - 8/8/2005 12:10 PMWhy did they open the payload doors again? What purpose does that serve or help and it seems a waste of power opening and closing again.
I think it's radiators? There are radiators inside the payload bay doors that are used to dissapate heat from the avionics, environmental control systems, etc... They can only reject heat when the doors are open and exposed to space.
There is a "flash boiler" cooling system that is used to provide cooling during launch and re-entry, but it is limited in it's capability or capacity. Don't know enough about the system to say if the cooling medium is consumed during operation, or if it can't handle the load during extended periods of operation?
rhwinger - 8/8/2005 12:36 PMSorry Stardust, didn't mean to echo you.
SimonShuttle:
Not to beat a dead horse, but I thought your question deserved a better answer. From "How Stuff Works":
Temperature ControlOuter space is an extremely cold environment and temperatures will vary drastically in different parts of the orbiter. You might think that heating the orbiter would be a problem. However, the electronic equipment generates more than enough heat for the ship. The problem is getting rid of the excess heat. So the temperature control system has to carry out two major functions:
To do this, the shuttle has two methods to handle temperature control:
The cabin heat exchanger also controls the cabin temperature. It circulates cool water to remove excess heat (cabin air is also used to cool electronic equipment) and transfers this heat to a Freon exchanger. The Freon then transfers the heat to other orbiter systems (e.g., cryogenic gas tanks, hydraulic systems) and radiates excess heat to outer space.