NASA's High Energy Astrophysics Science Archive Research Center
is for scientists and astronomy enthusiasts seeking actual data from a multitude of space-based
observatories. HEASARC is the primary archive for high-energy astronomy missions, in the extreme
ultraviolet, X-ray and gamma-ray wavelengths. On this site, you'll find archival data, multi-mission
software and analysis tools, and information about current and past observatory missions. These are
all available freely for your use.