Only a month after its launch, the Japanese/American Suzaku X-ray observatory (formerly known as Astro-E2), has lost the use of its flagship instrument. The X-ray Spectrometer (XRS),
the first high-energy calorimeter to fly in orbit, had been successfully cooled to 0.06° Kelvin (-273.09° C) on July 27th (JST), and demonstrated its expected high-resolution capabilities during onboard calibration tests. But before it could obtain its first glimpse of the sky, all of the instrument's helium coolant boiled away on August 8th due to a leak in its multi-stage cooling system.
Losing the XRS represents a severe blow to X-ray astronomy. The calorimeter was first planned to fly on the mission that eventually became the Chandra X-ray Observatory, but it split off in the early 1990s to fly on a different X-ray telescope that was soon cancelled. After that, the XRS was added to the Japanese Astro-E mission, which failed to reach orbit in 2000. Suzaku is Astro-E's replacement mission.
Meanwhile, Suzaku's other instruments, four CCD imagers and a hard X-ray detector, continue to work well. But it was the XRS that would have made Suzaku a world-class mission.