Netherlands, UK & USA

Spacecraft n°:

Netherlands spacecraft n°: 2

Infra Red Astronomy Satellite

Launch data:

Designation 13777 / 83004A
Launch date26 Jan 1983
Launch siteVa, SLC-2W
Launch vehicle Delta-3910 (#166)
MissionScientific: IR astronomy
Earth orbit on:
Perigee/Apogee 884/903 km
Inclination 99°
Period 102.9 min

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


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

End of life

Out of service23 Nov 1983


Mission details:


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)

Ref.: #7(JR774) - update: 12.03.20 Home