Mission History

There is a long history behind the Suzaku mission overall, and the XRS instruments in particular, going back about 20 years.

XRS was originally selected for AXAF, Advanced X-ray Astrophysics Facility in 1984, as its main spectroscopy instrument. In 1992, AXAF was re-organized into two missions: AXAF-I, the imaging mission, and AXAF-S, the spectroscopy mission with XRS. AXAF-I was named back to AXAF, and later renamed Chandra X-ray Observatory.

In 1993, NASA and ISAS reached an important agreement: rather than NASA flying AXAF-S, XRS will become the prime instrument on the 5th Japanese X-ray Astronomy satellite, ASTRO-E. People on both sides of the Pacific worked hard to make this mission a reality; in 1999, XRS and 5 XRTs were delivered from GSFC to Japan, integrated into the spacecraft, and tested extensively on the ground.

Then came the failure to place ASTRO-E into orbit in 2000 Fabruary.

This obviously was a traumatic experience for everybody involved with the mission. However, nobody just sat down and cried (well not for long, anyway). Within a few days, both Japanese and US scientists were hard at work, starting the long and hard process of requesting a reflight of the mission.

On the US side, GSFC scientists and collaborators submitted the Joule SMEX proposal on 2000 February 17. SMEX (SMall EXplorer) is a series of satellites small satellites that NASA launches. The Joule project was to launch the XRS and a single XRT; should the Japanese colleagues fail to secure approval for the reflight of the entire ASTRO-E mission, Joule would have carried out a significant fraction of the science goals on its own. SMEX proposals are evaluated by a peer review, and it was selected for Phase A study in 2000 September, with strong endorsement for the science from the review panel.

Their colleagues at ISAS were also hard at work, and secured government funding for Astro-E2 mission in 2000 December, and officially started the project in 2001 April.

Back on the US side, Joule team sought the approval for converting Joule to participation in Astro-E2. This process started in 2000 October and final approval was given on 2001 July 19 (read the press release).

You can read about the events since then elsewhere in the Learning Center.

• Timetable to Launch - Some of the major events leading up to the launch of Suzaku
• The XRS Road Trip - The journey of the XRS from the US to Japan to space
• Kevin's Kagoshima Journal: Episode II - Dr. Kevin Boyce's personal account of activities at the launch site.