lets you compute ephemerides and osculating elements over a -4500 to +4500 time span by numerical integration whose starting conditions are read from library files. SOLEX is a command-line utility which allows you to generate both screen and disk outputs, matching the JPL DE406 ephemerides very closely.
Ephemerides for 19,000 asteroids and 279 comets can be computed, and several coordinate options can be switched interactively.
Data can be read from custom files containing either positions and velocities or osculating elements, so that new bodies can be easily handled.
FindOrb, the companion program, enables you to determine orbits based on N-body numerical integration.
It inputs the observational data of a solar system body or an Earth's satellite and outputs the best fitting starting positions and velocities.
Non-gravitational parameters for comets (Ai coefficients) or satellites (drag coefficient) can also be optimized.
The computed starting vectors can be propagated to any other epoch as well as imported.