The High Energy Astrophysics Division (HEAD) is part of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. The Division's main focus is on X-ray astronomy via observations of high-energy sources with instruments aboard satellites, rockets, balloons, and the Space Shuttle. The Division also develops new instrumentation for future space missions to address the physical processes involved in generating X-rays, the amount of matter in the Universe, and the origin, evolution, and ultimate fate of the Universe.