NSSDC is a partner of NASA's other astrophysics "active archives" in making astrophysics data accessible. LAMBDA at Goddard makes cosmic microwave background data network-accessible. Other long-wavelength data are available from IRSA at Caltech. Optical and UV data are accessible from MAST at STScI. X-ray and gamma ray data are available from HEASARC at Goddard.
NSSDC is the permanent archive for most NASA astrophysics data. NSSDC holds various relatively recent data on CD-ROMs. Many older astrophysics data sets, from before the establishment of the active archives, are available on other offline media.