Hinotori, also known as ASTRO-A before launch, was a Japanese X-ray astronomy satellite.

It was developed by the Institute of Space and Astronautical Science (ISAS).

[3] It was launched successfully on February 21, 1981 using a M-3S rocket as the vehicle from Uchinoura Space Center (known at the time as Kagoshima).

After the start of normal operation, it observed a large solar flare and, a month later, succeeded in observing 41 flares of many sizes from the Sun.

[4] The name Hinotori is the Japanese word for Phoenix.