In this paper, we describe the first successful superconductivity experimen
t in space. The experiment aims to test the long-term survivability of high
-temperature superconductors (HTS's) under space conditions. Our system con
sists of a thin YBa2Cu3O7 him integrated with a cryocooler. The experiment
orbits the earth aboard the TECHSAT II satellite as of July 1998. Periodic
testing of the device returns data on its resistance, critical temperature,
and critical current. As of now, the superconducting film has shown a marg
inal degradation of its properties. We hope to provide the basic long-term
survivability data needed to advance applications of HTS's in space-based c
ommunication systems.