HIGH-TEMPERATURE SUPERCONDUCTING SPACE EXPERIMENT-II (HTSSE-II) CRYOGENIC DESIGN

At 60 to 80 K large performance gains are possible from high temperatu re superconducting (HTS) microwave devices for communications applicat ions. The High Temperature Superconducting Space Experiment II (HTSSE II) will demonstrate eight HTS experiments in space for up to 3 years of operation. HTSSE II is the first application of HTS technology to s pace. In addition to demonstrating HTS devices, an important secondary goal is to demonstrate the cryogenic technologies required for long l ife HTS space applications. HTSSE II utilizes a British Aerospace 80 K Stirling cycle cryocooler to refrigerate a central cryogenic bus of s even HTS experiments and has an additional stand-alone TRW I-ITS exper iment cooled by a TRW Stirling cycle cryocooler. The HTSSE II flight u nit has been assembled and has successfully passed vibration and therm al vacuum environmental tests. HTSSE II was developed on a fixed budge t and a fast track schedule of 24 months and is due to launch in March 1997 on the ARGOS spacecraft. This paper presents the design and test results of the cryogenic subsystem, cryocooler integration and a cryo genic coaxial cable I/O assembly.