What are thermal vacuum chambers used for at Goddard?
A spacecraft must survive various space environmental conditions while in orbit; three of which are temperature extremes, solar radiation, and vacuum. These three conditions are simulated one by one or simultaneously in thermal vacuum test chambers. Typically, whole spacecraft or spacecraft subsystems are installed inside the chamber and the chamber is closed and sealed. Mechanical, turbomolecular, and cryogenic vacuum pumps are used to evacuate the chamber of all air. Coils and plates inside the chamber carry temperature controlled liquid and gaseous nitrogen at temperatures varying from -310 degrees F to 300 degrees F. These coils are used to control the temperature of the test payload through radiative heat transfer. Typically, the temperatures are cycled from hot to cold to help simulate predicted payload temperatures caused by various payload operational and orbital conditions. Some chambers also have the ability to simulate solar radiation-sunlight by means of bright external lig
