The Astrophysics Data Facility (ADF) is developing the Astrophysics Multi-Mission Archive Search Engine (AMASE), an on-line astrophysics catalog. AMASE uses object-oriented data base (OODB) methodology to facilitate access to NASA's multimission and multispectral astrophysics data holdings. The catalog is a metadata data base consisting of scientific reference pointers to enable easy location of low-level space astrophysics data in the public archives. The metadata data base catalog contains both descriptions of mission-oriented data and published astronomical catalog data. OODB techniques are used to classify data products with scientific attributes, enabling queries across mission and spectral boundaries. The prototype system contains data from selected regions of the sky from the Roentgen Satellite (ROSAT) and the InfraRed Astronomical Satellite (IRAS) missions, totaling over 40,000 objects. More detailed information is available at URL http://bolero.gsfc.nasa.gov/adf/adf.html.