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.

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.

[6][7] 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.

It experienced a failure of 1st stage engine nozzle 42 seconds into the launch, causing control system breakdown and underperformance.