David A. Burt

Skipper -- An innovative U.S. and Russian university space science mission

Skipper is the third space experiment in the Bow Shock series to obtain aerothermochemistry and emission data from shock-heated layers. Onboard instrumentation will include two scanning spectrometers and 20 photometers. The spectrometers will scan over the range of 0.2 to 0.4 micrometers . The photometers will be designed to view the VUV and UV wavelengths with emphasis on atomic oxygen, Lyman-alpha, NO, OH, and N2+ wavelengths. The mission starts with launch into a 822 km circular orbit at 97 degree(s) inclination. Utah Sate University designed Skipper with their instrumentation module integrated on top of the Russian spacecraft bus. After spacecraft checkout in the 822 km orbit, the satellite uses hydrazine engines to change to an elliptical orbit with a perigee of about 180 km and begins the scientific measurements. The experimenters will then lower the perigee farther (in approximately 10 km steps) to increase the signal to noise ratios, as drag and thermal limits permit. These experiments will be completed in a two week period, followed by positioning the satellite for reentry over a Pacific test range. Additional data will be collected during the reentry (until the satellite burns up) using both onboard instrumentation and ground observation systems. Thermal modeling predicts that data can be collected down to about 80 km (at a speed of 7 km/sec).

Development of the SPIRIT III sensor

Space Dynamics Laboratory of Utah State University has built the SPIRIT III sensor that will be flown aboard the Midcourse Space Experiment (MSX) spacecraft and will operate for about 20 months. The MSX mission objective is to measure the spectral, spatial, and radiometric parameters of various orbital and suborbital targets; the earths airglow, aurora, and other upper atmospheric phenomena; and the celestial background. This paper discusses the development of the SPIRIT III sensor - the primary instrument for collecting long-wave infrared data during the MSX mission. SPIRIT III consists of a sensor system and 19 electronic units distributed near the sensor and in the electronics section. The sensor assembly consists of an extremely high off-axis-rejection telescope, a radiometer, and an interferometer, all of which are cooled to cryogenic temperatures by a solid-hydrogen-filled dewar/heat exchanger. In addition to these, there are a number of ancillary/diagnostic instruments.

Applying An Interferometer Spectrometer Aboard The Space Shuttle With A Payload Specialist In The Control Loop

A cryogenic interferometer/spectrometer (FTIR) has been developed at Utah State University as part of the CIRRIS-1A experiment for flight aboard the space shuttle. The inter-ferometer has been configured to optimize its operation by a payload specialist who may not have experience with interferometry but has had payload-specific training. CIRRIS-lA incorporates an automatic sequencer which can be used to operate pre-planned measurement routines. However, a command and monitor panel in the orbiter allows the payload specialist to select which measurement routines control the experiment; it also displays system and subsystem monitor values on its CRT display. The specialist can actuate various internal calibration sources and monitor interferometer performance by viewing the resulting waveforms on a video monitor. An automatic alignment system is provided in case the interferometer needs to be realigned during flight. Detailed operational procedures have been developed to guide the specialist through planned measurement and malfunction procedures and will be flown as part of the payload flight data file to allow in-flight anomalies to be resolved with minimal aid from the ground.