[X] My Assistant

[ktotam]

from Jonathan's Space Report:

The newly-launched Suzaku mission has lost the use of its premier instrument, the XRS, according to a JAXA press release on Aug 9. This is a big blow to X-ray astronomy, following a 15-year struggle to get the experiment into orbit.

Suzaku extended its optical bench on Jul 12, completing the most critical events of its early orbit operations. The first few element sets from Space Command seem to have confused Suzaku and its M34 final stage; the final stage is in a 248 x 540 km orbit and Suzaku was initially in a higher-perigee 295 x 540 km orbit. The satellite carries 100 kg of hydrazine for its four 23N main orbit raise thrusters which were used to reach its 565 x 573 km operational orbit by Jul 22. The XRS instrument was cooled down to 60 milliKelvin and showing good resolution on the internal calibration source by Jul 29. The three-stage cooler involves an active cooler surrounded by liquid helium and solid neon. Sadly, on around Aug 7 a leak in the cooler system resulted in loss of the liquid helium, and without the coolant XRS can't return the planned high resolution spectra.

XRS, the first X-ray microcalorimeter detector in orbit, was developed by NASA's Goddard Space Flight Center and Japan's ISAS science division of the JAXA space agency. It was originally planned to be aboard the AXAF (Chandra) mission, then split off into a separate AXAF-S mission that was later cancelled, and eventually added to the Japanese ASTRO-E mission which failed in 2000.

Calorimeter detectors are expected to play an important role in future X-ray missions, but although an XRS-type instrument successfully made astronomical observations on suborbital rocket flight NASA 27.140UH in 1996, there has been no long duration test of the technology to date. Suzaku's other instruments - four X-ray CCD telescopes and a high energy X-ray detector - are still being checked out and so far appear to be operating well.

[spdf]

The cause for the loss of the XRS was a communication problem between american and japanese teams. If you do a project in a foreign language than there are many rooms for misunderstandings.

For Akari it uses a diffrent system which was already tested in the IRTS mission in 1995. So this problem cannot happen to Akari.