IRTS Instruments

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

WeightTotal Weight : 183 kg
Cryostat : 128 kg
FPI+telescope : 9 kg
Electronics : 16 kg
Support structure : 18 kg
Others : 12 kg
Dimensions93cm 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"
T. Matsumoto
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
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Last Modified: 07 June 2016