ASTRO–E2Sixth in the series of small Japanese-US science satellites, scheduled for launch in early 2005 as the eventual successor to ASCA. Its immediate predecessor, ASTRO–E, was an X-ray imaging and spectroscopy satellite that carried instruments originally intended for NASA's AXAF program and was supposed to complement NASA's Chandra and ESA's XMM-Newton spacecraft. Unfortunately, ASTRO–E was lost during launch in Feb. 2000. ASTRO–E2 was developed as its replacement by the Institute of Space and Astronautical Science of the Japan Aerospace Exploration Agency (ISAS/JAXA) and other Japanese institutions in collaboration with NASA, Goddard Space Flight Center (GSFC), and the Massachusetts Institute of Technology (MIT).
ASTRO–E2's mission is to cover the whole energy range 0.2–600 keV with the three elements of its instrumentation: (1) an X-ray Spectrometer (XRS) using a cryogenically cooled X-ray microcalorimeter and located behind a conical-foil mirror, the X-Ray Telescope (XRT); (2) four X-ray CCD cameras comprising the X-ray Imaging Spectrometer (XIS), situated in the focal plane of an X-ray telescope co-aligned with the center of the XRS field of view; and (3) the hard X-ray detector (HXD), a non-imaging instrument consisting of a collimated system of ‘well’ detectors. The HXD's sensitivity is unusually high, and its equipment includes anticounters that screen out particle background and may also serve to detect high-energy events such as gamma-ray bursts. ASTRO–E2 is expected to achieve particularly high X-ray spectral resolution throughout the 0.4–10 keV energy band. In addition, it is expected to obtain imaging spectroscopy of extended sources using its nondispersive spectrometers covering a larger area with a greater sensitivity than has been achieved in earlier missions. ASTRO–E2 is scheduled to be placed into a circular orbit with an altitude of 550 km and an inclination of 31°.