The High Energy Astrophysics Science Archive Research Center (HEASARC) is the primary archive for high-energy astronomy missions, in the extreme ultraviolet, X-ray and gamma-ray wavelengths. This is the portal for the Chandra X-Ray Observatory archive.
The Mikulski Archive for Space Telescopes (MAST) is a NASA funded project to support and provide to the astronomical community a variety of astronomical data archives, with the primary focus on scientifically related data sets in the optical, ultraviolet, and near-infrared parts of the spectrum.
NExScI is the science operations and analysis center for NASA's Exoplanet Exploration Program. It provide tools and archives for the exoplanet community.
NED is a master list of extragalactic objects for which cross-identifications of names have been established, accurate positions and redshifts, and some basic data collected.
IRSA archives the science products from NASA's infrared and submillimeter projects, such as Spitzer, WISE, IRAS and 2MASS. IRSA also provides data from several ESA mission that NASA participated in including: ISO, Planck and Herschel.
SIMBAD is operated by the Centre de Données astronomiques de Strasbourg (CDS) in France. It is a bibliographic database of astronomical objects of interest outside the solar system: stars, galaxies, interstellar/intergalactic medium sources, clusters of stars/galaxies, exoplanets, gravitational sources, and transient events. For each object, it provides its bibliography, fundamental data (astrometry, velocity/redshift, magnitudes, etc.), as well as collections of additional measurements.
A digital library portal for researchers in astronomy and physics, operated by the Center for Astrophysics | Harvard & Smithsonian under a NASA grant.