TENMA, also known as ASTRO-B, was a Japanese X-ray astronomy satellite launched to study celestial X-ray sources. TENMA was designed to conduct X-ray observations of celestial objects, including black holes, neutron stars, supernova remnants, and active galactic nuclei. The satellite aimed to advance our understanding of high-energy astrophysical phenomena.

The primary instrument on TENMA, consisting of X-ray mirrors and detectors to observe X-ray emissions from celestial objects. It had a spatial resolution of about 3 arcminutes.