Advanced Telescope for High Energy Astrophysics
Advanced Telescope for High-ENergy Astrophysics (Athena) is an X-ray observatory mission selected by European Space Agency (ESA) within its Cosmic Vision program to address the 'Hot and Energetic Universe' scientific theme. The primary goals of the mission are to map hot gas structures, determine their physical properties, and search for supermassive black holes.
Source: Wikipedia — Advanced Telescope for High Energy Astrophysics (CC BY-SA 4.0)