The Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS 1A) instrument, launched on the Shuttle Discovery (STS-39) on 28 April 1991, was developed to characterize the phenomenology and dynamics of ionospheric processes. The primary objective of the CIRRIS 1A mission was to obtain spectral and spatial measurements of infrared atmospheric emissions in the spectral region between 2.5 and 25 microns over altitudes ranging from the Earth's surface to 260 km. The primary sensors are a Michelson interferometer/spectrometer and a multi-spectral radiometer, which share a common high off-axis rejection telescope. The sensor/telescope complex is enclosed in a cyogenic dewar. Excellent data were obtained from this mission, and preliminary analysis shows that all sensors performed well. This paper describes the experiment hardware, summarizes instrument performance during flight, and presents examples of significant results.