Article · Wikipedia archive · Last revised Jun 9, 2026

Tenma

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.

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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)1
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 19882
Decay date19 January 1989
Orbital parameters
Reference systemGeocentric1
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),3a and it had a superior temporal and spectral sensitivity compared to its predecessor.5

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 1985,6 however it remained in sporadic contact until 17 December 1988.2 It reentered the atmosphere on 19 January 1989.b

Highlights

  • Discovery of the iron helium-like emission from the galactic ridge.6
  • Iron line discovery and/or study in many LMXRB, HMXRB and AGN.2
  • Discovery of an absorption line at 4 keV in the X1636-536 Burst spectra.
References

References

Notes

  1. Tenma was the third Japanese X-ray observatory launched, as CORSA-A was lost in a launch failure in 1976.4
  2. The NORAD catalog considers Tenma's decay date occurred on 17 December 1988.7

Citations

  1. G. D. Krebs. "Astro B (Tenma)". Gunter's Space Page. Retrieved 18 August 2025.
  2. "Tenma | Spacecraft". isas.jaxa.jp. JAXA / ISAS. Retrieved 19 August 2025.
  3. Y. Tanaka; M. Fujii; H. Inoue; et al. (1984). "X-ray astronomy satellite Tenma" (PDF). Publications of the Astronomical Society of Japan. 36 (4): 641–658. Bibcode:1984PASJ...36..641T. doi:10.1093/pasj/36.4.641. ISSN 0004-6264.
  4. G. D. Krebs. "Corsa A, B (Hakucho)". Gunter's Space Page. Retrieved 20 August 2025.
  5. C. Simpson (1984). "Tenma – Japan's X-ray satellite". Spaceflight. Vol. 26. p. 284. Bibcode:1984SpFl...26..284S. ISSN 0038-6340.
  6. L. Angelini; J. Allen (7 October 2003). "The Tenma [Astro-B] satellite". heasarc.gsfc.nasa.gov. NASA / GSFC. Retrieved 20 August 2025.
  7. T. S. Kelso. "CelesTrak: Search Satellite Catalog". Retrieved 3 June 2020.
External links