Welcome to DARTS/ASCA
ASCA (Advanced Satellite for Cosmology and Astrophysics) is the fourth Japanese X-ray astronomy satellite launched on February 20, 1993 (Tanaka et al. 1994). The collaboration between Japanese and US scientists has been carried out in the developments of the X-ray telescopes, the X-ray CCD cameras, and software.
ASCA observed more than 3000 targets before stopping scientific observations on July 14, 2000, when a huge solar flare and a violent magnetic storm occurred. Consequently, atmospheric density around the ASCA orbit and the air-drag disturbance suddenly increased, resulting in a great turbulence in the satellite attitude and a significant electric power shortage.
The observation log is provided by the X-ray astronomy group at ISAS. ISAS continued monitoring ASCA until the satellite reentered the atmosphere on March 2, 2001.