AXIS (Advanced X-ray Imaging Satellite) is a NASA Probe Mission Concept to be the premier high angular resolution X-ray mission of the mid-2020s. The need for sub-arc sec resolution in astrophysics is evident across the entire electromagnetic spectrum. It is essential for resolving the critical physical scales of virtually all classes of objects and for extending such studies to the highest redshift. AXIS will follow in the footsteps of the spectacularly successful Chandra X-ray Observatory with similar or higher angular resolution and ~10x Chandra count rates.
Read the full Probe Mission Concept Proposal here.