Low pressure drop condenser/heat pipe heat exchanger

A heat exchanger adapted for testing in a 1 G gravity environment and operation in a microgravity environment, comprising:

• an elongated heat pipe including a portion adapted to be coupled to a heat-rejecting plate for rejecting heat, and also including an elongated cylindrical portion adapted for receiving heat which is to be rejected;
• a source of a flow of heat-laden fluid which is to be cooled;
• a plurality of channels helically wound about an thermally coupled to said elongated cylindrical portion of said heat pipe, said plurality of channels being coupled for receiving said heat-laden fluid, said channels being wetted by said fluid and having cross-sectional dimensions selected so that the surface tension forces of said fluid are predominant relative to the gravitational forces on said fluid in a 1 G gravity environment, and the helix dimensions being selected so that centrifugal forces are at least significant relative to said gravitational forces in said 1 G gravity environment, whereby heat is transferred from said fluid in said channels to said heat pipe for rejection, resulting in cooled fluid, in much the same manner in a microgravity environment as in a 1 G gravity environment, and testing can therefore take place in a 1 G gravity environment, and operation can take place in a microgravity environment.