From the Union of Concerned Scientists (UCS):
The UCS Satellite Database is a listing of the more than 900 operational satellites currently in orbit around Earth. Our intent in producing the database is to create a research tool for specialists and non-specialists alike by collecting open-source information on operational satellites and presenting it in a format that can be easily manipulated for research and analysis. It is available as both a downloadable Excel file and in a tab-delimited text format. A version is provided, as well, in which the “Name” column contains only the official name of the satellite in the case of government and military satellites, and the most commonly used name in the case of commercial and civil satellites. The database is updated roughly quarterly. It includes basic information about the satellites and their orbits, but does not contain the detailed information necessary to locate individual satellites.
The database contains 24 types of data for each satellite, including technical information about each satellite (mass, power, launch date, expected lifetime) and its orbit (apogee, perigee, inclination, and period), as well as what the satellite is used for, and who owns, operates, and built the satellite.
This version of the database includes satellites launched through December 31, 2011. The database currently contains 994 actively working satellites