Suzaku (satellite)

Suzaku (formerly ASTRO-EII) was an X-ray astronomy satellite developed jointly by the Institute of Space and Aeronautical Science at JAXA and NASA's Goddard Space Flight Center to probe high-energy X-ray sources, such as supernova explosions, black holes and galactic clusters. It was launched on 10 July 2005 aboard the M-V launch vehicle on the M-V-6 mission. After its successful launch, the satellite was renamed Suzaku after the mythical Vermilion bird of the South.^[4]

Suzaku (ASTRO-EII)

A picture of a fully integrated Astro-E2 before vibration tests at ISAS/JAXA.
Names	ASTRO-EII
Mission type	Astronomy
Operator	JAXA / NASA
COSPAR ID	2005-025A
SATCAT no.	28773
Website	www.jaxa.jp/projects/sat/astro_e2
Mission duration	2 years (planned) 10 years 1 month 23 days (achieved)
Spacecraft properties
Spacecraft type	ASTRO
Bus	ASTRO-E
Manufacturer	Toshiba[1]
Launch mass	1,706 kg (3,761 lb) [2]
Dimensions	2 metres x 5 metres
Power	500 watts
Start of mission
Launch date	10 July 2005, 03:30:00 UTC
Rocket	M-V # 6
Launch site	Uchinoura Space Center, Uchinoura, Kagoshima
End of mission
Deactivated	2 September 2015
Decay date	5 January 2025[3]
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Perigee altitude	550 km (340 mi)
Apogee altitude	550 km (340 mi)
Inclination	31°
Period	96 minutes
Instruments
X-ray Spectrometer-2 (XRS-2) X-ray Imaging Spectrometer (XIS) Hard X-ray Detector (HXD)

ASTRO-E

The M-V launch vehicle carrying ASTRO-E veering off course after launch on 10 February 2000.
Mission type	Astronomy
Operator	Institute of Space and Astronautical Science (ISAS) / NASA
COSPAR ID	2005-025A
SATCAT no.	28773
Mission duration	Failed to orbit
Spacecraft properties
Spacecraft type	ASTRO
Bus	ASTRO-E
Manufacturer	Toshiba
Launch mass	1600 kg
Dimensions	2 metres x 5 metres
Power	500 watts
Start of mission
Launch date	10 February 2000, 01:30:00 UTC
Rocket	M-V # 4
Launch site	Kagoshima Space Center
End of mission
Decay date	Failed to orbit
Orbital parameters
Reference system	Geocentric orbit (planned)
Regime	Low Earth orbit
Perigee altitude	550 km (340 mi)
Apogee altitude	550 km (340 mi)
Inclination	31.0°
Period	96.0 minutes
Instruments
X-ray Spectrometer (XRS) X-ray Imaging Spectrometer (XIS) Hard X-ray Detector (HXD) X-ray Telescope (XRT)

Just weeks after launch, on 29 July 2005, the first of a series of cooling system malfunctions occurred. These ultimately caused the entire reservoir of liquid helium to boil off into space by 8 August 2005. This effectively shut down the X-ray Spectrometer-2 (XRS-2), which was the spacecraft's primary instrument. The two other instruments, the X-ray Imaging Spectrometer (XIS) and the Hard X-ray Detector (HXD), were unaffected by the malfunction. As a result, another XRS was integrated into the Hitomi X-ray satellite, launched in 2016, which also was lost weeks after launch. A Hitomi successor, XRISM, launched on 7 September 2023, with an X-ray Spectrometer (Resolve) onboard as the primary instrument.

On 26 August 2015, JAXA announced that communications with Suzaku had been intermittent since 1 June 2015 and that the resumption of scientific operations would take a lot of work to accomplish, given the spacecraft's condition.^[5] Mission operators decided to complete the mission imminently, as Suzaku had exceeded its design lifespan by eight years at this point. The mission came to an end on 2 September 2015, when JAXA commanded the radio transmitters on Suzaku to switch themselves off.^[6][7]

Spacecraft instruments

Suzaku carried high spectroscopic resolution, very wide energy band instruments for detecting signals ranging from soft X-rays up to gamma-rays (0.3–600 keV). High-resolution spectroscopy and wide-band are essential factors in physically investigating high-energy astronomical phenomena, such as black holes and supernovas. One such feature, the K-line (x-ray), may be key to more direct imaging of black holes.

• X-ray Telescope (XRT)
• X-ray Spectrometer-2 (XRS-2)
• X-ray Imaging Spectrometer (XIS)
• Hard X-ray Detector (HXD)
  • Uses Gadolinium Silicate crystal (GSO), Gd₂SiO₅(Ce)^[8]
  • Uses Bismuth Germanate crystal (BGO), Bi₄Ge₃O₁₂^[8]

• 
  X-ray Telescope (XRT)
• 
  Hard X-ray Detector (HXD)
• 
  X-ray Imaging Spectrometer (XIS)
• 
  X-ray Spectrometer (XRS)

Results

Suzaku discovered "fossil" light from a supernova remnant.^[9]

ASTRO-E

Suzaku was a replacement for ASTRO-E, which was lost in a launch failure. The M-V launch vehicle on the M-V-4 mission launched on 10 February 2000 at 01:30:00 UTC. It experienced a failure of 1st stage engine nozzle 42 seconds into the launch, causing control system breakdown and underperformance.^[10][11] Later stages could not compensate for underperformance, leaving payload in 250 miles (400 km) x 50 miles (80 km) orbit and subsequent reentry and crashed with its payload into the Indian Ocean.^[12][13]