A high-temperature superconductivity (HTSC) flight experiment from the payload bay of the Space Shuttle Orbiter to the Advanced Communications Technology Satellite (ACTS) is being breadboarded. This proposed experiment, a joint project between the Johnson Space Center and the Lewis Research Center, would use a Ka-band (20 GHz) HTSC phased array antenna and front-end electronics (low-noise amplifier) to receive a downlink communications signal from the ACTS. A conventional receiver demodulates the encoded telemetry signal which is then turned around and transmitted back to ACTS and die ground. The HTSC phased array has nine 4 x 4 microstrip patch antenna subarrays which when properly phased, provide approximately 24 dB of boresight gain. A 2 x 2 HTSC microstrip patch has been built and tested. A Ka-band receiver, transmitter, modem, encoder, decoder, etc., are now being built and tested. Link analyses and interface problems with the Orbiter are addressed in the paper in addition to the design, fabrication, and testing of various subsystems used in the communication link.
