Corsa-b hakucho.gif
Mission typeX Ray Celestial Observation
OperatorInstitute of Space and Astronautical Science (Japan)
COSPAR ID1979-014A
SATCAT no.11272
Spacecraft properties
Launch mass96.0 kilograms (211.6 lb)
Start of mission
Launch date21 February 1979 UTC
RocketM-3C-Rocket (mission 4)
Launch siteUchinoura Space Center, Kagoshima Prefecture, Japan
End of mission
Decay dateApril 15, 1985

Hakucho (also known as CORSA-b before launch; CORSA stands for Cosmic Radiation Satellite) was Japan's first X-ray astronomy satellite, developed by the Institute of Space and Aeronautical Science (then a division of the University of Tokyo). It was launched by the ISAS M-3C rocket on the M-3C-4 mission on February 21, 1979 and reentered the atmosphere on April 15, 1985.[1]

It was a replacement for the CORSA satellite which failed to launch due to rocket failure on February 4, 1976.[2]


  • Discovery of soft X-ray transient Cen X-4 and Aql X-1
  • Discovery of many burst sources
  • Long-term monitoring of X-ray pulsar (e.g. Vela X-1)
  • Discovery of 2 Hz variability in the Rapid Burster later named Quasi Period Oscillation.

See also


  1. ^ https://celestrak.com/satcat
  2. ^ https://space.skyrocket.de/doc_sdat/corsa-a.htm
  • isas.jaxa.jp
  • heasarc.gsfc.nasa.gov