Mission Overview

Hakucho (CORSA-b) satellite was the first X-ray astronomy satellite developed by developed by the Institute of Space and Aeronautical Science at the University of Tokyo (currently ISAS/JAXA).
Its mission was to observe X-ray burst sources and to obtain the broad-spectrum and intensity variations of X-ray celestial objects.

It was launched by the M-3C rocket No.4 from the Kagoshima Space Center (currently Uchinoura Space Center) on February 21, 1979, and completed its operation on April 15, 1985.
The satellite weighed 96 kg and was placed into a nearly circular orbit with a perigee altitude of 545 km, an apogee altitude of 577 km, an inclination of 30 degrees, and a period of 96 minutes.

Utilizing the Earth’s magnetic field to control its spin axis, Hakucho observed numerous X-ray sources.

From DARTS, only raw telemetry data archives are available. Higher-level processed data, documentation necessary for data processing, and software for scientific analysis are not provided, which limits comprehensive scientific analysis support.

Achievements

Eight new X-ray burst sources were discovered by the modulation collimator onboard Hakucho. This has provided new insights into the physical properties of X-ray bursts and the mechanisms of their bursts. It also played an active role in simultaneous observations with optical observatories around the world.

Other observations included periodic variations of X-ray pulsars and black holes, which greatly contributed to the development of early X-ray astronomy and provided an important foundation for subsequent research.