ATHENA (Advanced Telescope for High-ENergy Astrophysics) is an X-ray telescope,  selected in June 2014 as the second large (L-class) mission in ESA's Cosmic Vision Programme. It is designed to study the hot and energetic universe, answering questions about the growth of back holes. To achieve the mission's science objectives, ATHENA carries a cryogenic X-ray spectrometer called the X-ray Integral Field Unit (X-IFU) and a Wide Field Imager (WFI), to which IWF will contribute.

ATHENA is planned for launch in 2037. It will operate at L2, the second Lagrange point of the Sun-Earth system, in a large amplitude halo orbit.

Further information on ATHENA is found at the site of the Athena Community Office and at ESA.