Hinotori (satellite)

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). Its primary mission was to study of solar flares emanating from the Sun during the solar maximum.^[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. It reentered the atmosphere on July 11, 1991.^[4] The name Hinotori is the Japanese word for Phoenix.

Hinotori

Names	Astro-A
Mission type	Astronomy
Operator	ISAS
COSPAR ID	1981-017A
SATCAT no.	12307
Spacecraft properties
BOL mass	185 kilograms (408 lb)
Start of mission
Launch date	21 February 1981, 00:30:00 (1981-02-21UTC00:30Z) UTC[1]
Rocket	Mu-3S
Launch site	Mu Pad, Kagoshima
Contractor	ISAS
End of mission
Decay date	11 July 1991 (1991-07-12)
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Eccentricity	0.00395
Perigee altitude	548 kilometres (341 mi)
Apogee altitude	603 kilometres (375 mi)
Inclination	31.3 degrees
Period	96.2 minutes
Epoch	21 February 1981, 04:30:00 UTC[2]
ASTRO program Tenma (ASTRO-B) →

Instruments

• Solar flare X-ray imager (SXT)
• Solar soft X-ray bright line spectrum analyzer (SOX)
• Solar soft X-ray monitor (HXM)
• Solar flare monitor (FLM)
• Solar gamma ray monitor (SGR)
• Particle ray monitor (PXM)
• Plasma electron density measurement instrument (IMP)
• Plasma electron temperature measurement instrument (TEL)

Highlights

• Observational data of the maximum period of solar activity
• Discovery of high-temperature phenomena reaching up to 50 million °C and clouds of light-speed electrons floating in the corona of the Sun