“Significant advances in science always seem to take place when the state of the art in instrumentation improves. NASA’s next Great Observatory, the Advanced x-ray Astrophysics Facility (AXAF), represents such an advance. AXAF is an observatory designed to study the x-ray emission from all categories of astronomical objects, from normal stars to quasars. Major elements of the observatory—the optics and scientific instruments—are nearing completion this year in preparation for calibration and eventual launch in late 1998. AXAF has broad scientific objectives and an outstanding capability to provide high-resolution (<1 arcsec) images, spectrometric imaging, and high-resolution dispersive spectroscopy over the energy bandwidth from 0.1-10 keV.”