picture of the encyclopedia
previous next
Version 0.81 comes with a new web design! Please allow popups for navigation.


Infra Red Astronomy Satellite


Designation 13777 / 83004A
Launch date 26 Jan 1983
Country of origin Netherlands, United Kingdom and United States
Mission Scientific: IR astronomy
Perigee/Apogee 884/903 km
Inclination 99°
Period 102.9 min
Launch vehicle Thor Delta #166

It mapped 250,000 IR sources in the 300 days before its helium coolant was exhausted.

On 29 Jan 2020 IRAS had a near miss with Poppy 5B, less than 100 meters appart.

End of life

Out of service 23 Nov 1983

Technical data


Industrial responsabilities Netherlands Aerospace Agency (bus)
NASA Ames Research Center, JPL (telescope)
SERC (TT&C and data collection)
Prime contractors: ICIRAS (bus)
Ball Aerospace (telescope)
Perkin-Elmer (optics)
Mass at launch 1077 kg
Telescope mass 810 kg
Diameter 2.2 m
Height 3.6 m
Solar array 5 m² (2 panels)
Stabilization 3-axis
DC power EOL: 500 W
Design lifetime 11 months


Ritchey-Chretien-type reflecting telescope with a local plane array of 62 IR detectors surrounded by a dewar containing 475 l of liquid helium. Plus 2 photometers and a low-resolution spectrometer.

Telescope diameter 0.57 m
Focal length 5.5 m
Field of view 30 arcmin

Spectral range:
IR Telescope (band 1) 8.5-15 µm
(band 2) 19-30 µm
(band 3) 40-80 µm
(band 4) 83-119 µm
Spectrometer 7.4-23 µm
Short wavelength photometer 4.1-8 µm

Cooling system by evaporated helium
Temperature control 2 K
Telemetry/data S-band (1 Mbps)

© TBS Internet, all rights reserved. All reproduction, copy or mirroring prohibited. Legal notice
francais anglais contact