Tenma

Tenma
Tenma (Japanese for "Pegasus")
NamesASTRO-B
Mission typeX-ray astronomy
OperatorISAS
COSPAR ID1983-011A
SATCAT no.13829
Mission duration5 years, 9 months, 27 days
Spacecraft properties
Launch mass216 kg (476 lb)
Dimensions0.94 m × 0.895 m (3.08 ft × 2.94 ft)
Start of mission
Launch date20 February 1983, 05:10 UTC
RocketM-3S
Launch siteKagoshima Space Center
End of mission
DisposalDecommissioned
Last contact17 December 1988
Decay date19 January 1989
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude489 km (304 mi)
Apogee altitude503 km (313 mi)
Inclination31.5°
Period94 minutes

Tenma, known as ASTRO-B before launch, was a Japanese X-ray astronomy satellite developed by the Institute of Space and Astronautical Science. It was launched on 20 February 1983, using a M-3S rocket on the M-3S-3 mission. It was the second X-ray observatory successfully operated by Japan after Hakucho (CORSA-B), and it had a superior temporal and spectral sensitivity compared to its predecessor.

Battery failure in July 1984 caused the operation to become limited, and continuing problems lead to the termination of X-ray observation on 11 November 1985, however it remained in sporadic contact until 17 December 1988. It reentered the atmosphere on 19 January 1989.