BlackCAT, also supported by Exolaunch, is an X-ray telescope on a CubeSat platform that will observe X-ray flares from active galaxies with supermassive black holes as well as gamma-ray bursts, the most powerful explosions in the cosmos. In addition to nearby short gamma-ray bursts that may accompany space-time ripples called gravitational waves, BlackCAT also will study rare and bright bursts from the early universe.
WIKI
https://en.wikipedia.org/wiki/BlackCAT