Submillimeter Wave Astronomy Satellite performance on the ground and in orbit
Journal or Book Title
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
The Submillimeter Wave Astronomy Satellite (SWAS), which was launched in 1998 December, is a NASA mission dedicated to the study of interstellar chemistry and star formation. SWAS is conducting pointed observations of molecular clouds throughout our Galaxy in either the ground state or a low-lying transition of five astrophysically important species: O2, C I, H218O, 13CO, and H216O at approximately 487, 492, 548, 551, and 557 GHz, respectively. The SWAS instrument is comprised of a 54 cm × 68 cm off-axis Cassegrain telescope feeding two independent heterodyne receivers with Schottky barrier diode mixers, passively cooled to about 175 K. An Acousto-Optical Spectrometer (AOS) provides ~1 MHz (0.6 km s-1) frequency resolution and 1400 MHz (840 km s-1) total bandwidth with 350 MHz (210 km s-1) per line for spectral analysis. SWAS was fully characterized during ground-based testing, and all performance parameters were verified on-orbit. During its on-orbit operation, SWAS observed more than 200 astronomical objects with more than 5000 lines of sight. This paper describes the tests conducted and compares the ground-based test results with the on-orbit test results.
Tolls, V; Melnick, GJ; Ashby, MLN; Bergin, EA; Gurwell, MA; Kleiner, SC; Patten, BM; Plume, R; Stauffer, JR; Wang, Z; Zhang, YF; Chin, G; Erickson, NR; Snell, Ronald L.; Goldsmith, PF; Neufeld, DA; Schieder, R; and Winnewisser, G, "Submillimeter Wave Astronomy Satellite performance on the ground and in orbit" (2004). ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES. 619.