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.

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 be difficult to accomplish given the spacecraft's condition. 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.