The High Energy Astrophysics Division (HEAD) was founded in 1973 with the merging of high energy scientists at SAO with a new group led by Dr. Riccardo Giacconi (Nobel Prize in Physics , 2002; ) who became its first Associate Director. Over the past 30 years, HEAD has grown from a group of about 10 scientists to a combined staff about 300 including just over 125 research scientists. The AD's have included Riccardo Giacconi (1973-1981 ), Harvey Tananbaum (1981-1991; CXO director 1991-) member NAS), Steve Murray (1992-2003; PI HRC, CFA Deputy Director for Science 2005-), and Roger Brissenden (2003-; CXO manager 1993-). Supporting the HEAD operations and research staff is a budget of approximately $60M mostly from external contracts and grants.

The primary focus of HEAD has been a series of major X-ray astronomy missions including UHURU (12 December 1970, the seventh anniversary of Kenyan independence, to March 1973.), Einstein (12 November 1978 - April 1981), and Chandra (launched 23 July 1999). In addition, members of the division made major contributions to ANS, HEAO-1 (August 1977 - January 1979), ROSAT (June 1990 - February 1999) and a series of solar experiments including TRACE (launched July 1999), Hinode (nee Solar-B, launched September 2006 ), SDO and Solar & Stellar X-Ray Group .

The Einstein Observatory (nee HEAO-B), the second of NASA's three High Energy Astrophysical Observatories and the first fully imaging X-ray telescope, was developed and operated by HEAD. With angular resolution, moderate field of view, and a sensitivity several 100 times greater than any previous mission, the Einstein Observatory completely altered our view of the X-ray sky with observations spanning the full range of celestial objects including planets, stars, normal galaxies, collapsed objects from stellar mass black holes to AGN, clusters of galaxies, and detailed observations of the components of the X-ray background. It was also the first NASA X-ray mission to provide a Guest Observer program. In addition to managing the development of the observatory and its X-ray mirrors, HEAD provided the two imaging focal plane instruments (High Resolution Imager and Imaging Proportional Counter)

Following the Einstein era, HEAD participated in the ROSAT mission (ROSAT GOF) with the development of the second generation High Resolution Imager and development and participation in community-wide software tools.

Currently, HEAD operates the Chandra X-ray Observatory, one of NASA's Great Observatories, named in honor of Subrahmanyan Chandrasekhar (Nobel Prize in Physics, 1983;) With its subarcesecond angular resolution and large effective area, Chandra has revolutionized the study of the X-ray background, normal and active galaxies, supernova remnants, planets, galaxy clusters. During the development phase of the Chandra Observatory (nee AXAF), HEAD provided guidance on the development of the X-ray optics and developed a third generation High Resolution Camera (HRC). As directed by NASA, HEAD operates the Chandra X-ray Observatory, solicits and plans observations, and provides data analysis tools for the community.

HEAD maintains a strong interest in new missions with a team working on instruments and concepts for future missions. Major efforts include laboratory development through the Center for X-ray Technology and laboratory development of high energy resolution microcalorimeters. Studies and planning for the future include Constellation-X (a collaboration of SAO and GSFC) and concepts for Generation-X, a high angular resolution telescope with area 1000 times that of Chandra.

The The Solar and Stellar X-ray Group, part of HEAD, maintains an operations center for Hinode. HEAD also manages the NASA Astrophysics Data System with 14 sites around the world containing more than 5 million entries. HEAD is a partner with GSFC in the HEASARC data archive.