OPERA

OPERA is a tool allowing to estimate long and middle term Earth reentry dates (some months to one week in advance) thanks to TLE (Two Lines Elements) and allows also to compute the information on other parameters as S/M (Surface on Mass ratio) or maneuvers previously occurred. OPERA is also able to generate automatic Pdf reports with a synthesis of maneuver activity of a given object.

 OPERA is usable via three modes:

• GUI : its utilization is made user-friendly thanks to a graphical user interface (developed using GENIUS and GENOPUS) facilitating context elaboration and results exploitation,
• Batch with some initial parameters and a context file,
• Library via its Java interface. This mode allows to use it inside higher level tools.

Its initialization is made by:

• A list of initial orbital parameters thanks to TLE,
• Solar activity files
• Several other specific parameters as the reentry altitude or how to filter TLE inputs.

For flight dynamics aspects, OPERA is fully based on the PATRIUS library and specially about the orbit extrapolation, the propagation is done thanks to the STELA propagator that allows to get interesting CPU time by comparison to a full numerical propagator while keeping sufficient precision relative to the reentry date.