Contains over 600,000 asteroids indexed form multiple databases. Includes mass, composition, and estimated potential economic value based on mass and spectral types. Acquired by Planetary Resources in May 2013 and the code is available on GitHub.
JPL Small Body Database
Maintained by the Jet Propulsion Laboratory and NASA. Provides data for asteroids and comets including orbital parameters and diagrams. Updated daily.
Minor Planet Center Database
MPC is the single worldwide location for receiving and distributing positional data of asteroids and other natural satellites in our system. Operates under the International Astronomical Union and maintains an extensive database.
MIT SMASS Survey
Small Main-Belt Asteroid Spectrographic Survey of 1447 asteroids. This survey was far more accurate than the past efforts and resulted in a new classification system for asteroids introduced in 2002.