OSO 8

USA

Launch data:

Designation	07970 / 75057A
Launch date	21 Jun 1975
Launch site	CC, LC-17B
Launch vehicle	Delta-1910 (#112)
Mission	Scientific: Sun observation
Earth orbit:
Perigee/Apogee	539/553 km
Inclination	32.9°
Period	95.6 min
Mass at launch	1064 kg

Artist's impression of OSO-8 in orbit

Payload:

GSFC Cosmic X-Ray Spectroscopy Experiment (GCXSE)
Detector A (2-60 keV): Eff. area = 263 cm2, FOV = 5°
Detector B (2-20 keV): Eff. area = 37 cm2, FOV = 3°
Detector C (2-60 keV): Eff. area = 237 cm2, FOV = 5°
High Energy Celestial X-ray Experiment
0.01-1 MeV eff. area 27.5 cm2, FOV 5°
Soft X-ray Background Radiation Experiment
0.15-45 keV eff. area 51.8 cm2, 43.0 cm2, 41.7 cm2, FOV 2.7° with 3° spatial resolution
Graphite Crystal X-ray Spectrometer 2-8 keV, FOV 3°

Science Highlights:

Iron-line detection in the X-ray spectra of a cluster of galaxies.
Detection of Black-Body spectrum from X-ray bursts.
Set upper limit on the polarization of radiation from several X-ray binaries.

End of life

Out of service	01 Oct 1978
Decay	09 Jul 1986

Mission details:

While OSO-8's primary objective was to observe the Sun, four instruments were dedicated to observations of other celestial X-ray sources brighter than a few milliCrab. OSO-8 ceased operations on 1 October 1978.

Ref: #1, #6m - update: 11.08.11