The Infrared Telescope in Space (IRTS) is a cryogenically cooled small infrared telescope that will fly aboard the small space platform Space Flyer Unit. It will survey approximately 10% of the sky with a relatively wide beam during its 20 day mission. Four focal-plane instruments will make simultaneous observations of the sky at wavelengths ranging from 1 to 1000 microns. The IRTS will provide significant information on cosmology, interstellar matter, late-type stars, and interplanetary dust. This paper describes the instrumentation and mission.
Characteristics of the IRTS
|Weight||Total Weight : 183 kg|
|Cryostat : 128 kg|
|FPI+telescope : 9 kg|
|Electronics : 16 kg|
|Support structure : 18 kg|
|Others : 12 kg|
|Dimensions||93cm diameter (cryostat) x 135 cm (including aperture shade)|
|Power consumption||80 W maximum|
|Cryostat||Superfluid helium, 90 liters|
|FPI temperature : 1.9 K|
|Cold lifetime : > 35 days after launch|
|Telescope||15 cm diameter F/4 Richey-Chretien type|
|Effective collecting area : 113 cm2|
|FPIs||Near-Infrared Spectrometer (NIRS)|
|Mid-Infrared Spectrometer (MIRS)|
|Far-Infrared Line Mapper (FILM)|
|Far-Infrared Photometer (FIRP)|
|Telemetry||Data rate : 6 kbits/s (visible orbit), 3 kbits/s (invisible orbit)|
|Observation||20 days, uniform sky survey|
|Sky coverage||Approximately 10% of the entire sky|
Cross Section of IRTS
Telescope & FPI of the IRTS (Provided by ISAS.)
FPIs of the IRTS
Four scientific instruments, the Near-Infrared Spectrometer (NIRS), the Mid-Infrared Spectrometer (MIRS), the Far-Infrared Line Mapper (FILM), and the Far-Infrared Photometer (FIRP) are installed in the focal plane of the telescope together with a near-IR sar sensor.
For more details, refer to the following publications.
- "The Infrared Telescope in Space (IRTS)"
H. Murakami, J. Bock, M. M. Freund, H. Guo, T. Hirao, A. E. Lange, H. Matsuhara, T. Matsumoto, S. Matsuura, T. J. McMahorn,
M. Murakami, T. Nakagawa, M. Noda,K. Noguchi, H. Okuda, K. Okumura, T. Onaka, T. L. Roellig, S. Sato, H. Shibai, T. Tanabe,
T. Watabe, T. Yagi, N. Yajima, and M. Yui
1994, The Astrophysical Journal, vol.428, p.354-362
- "IRTS Mission"
1996, in SPIE Proc.2817, Infrared Spaceborne Remote Sensing IV ed. M. S. Scholl and B. F. Andresen, p.238-247
- "Flight performance of the Infrared Telescope in Space (IRTS)"
Hiroshi Murakami, Hiroshi Shibai, Takashi Onaka, and Takanori Hirao
1996, in SPIE Proc. 2744, Infrared Technology and Applications XXII ed. B. F. Anderesen and M. S. Scholl, P.68-74