single impulse deorbit from an elliptical orbit - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: HP Prime Software Library (/forum-15.html) +--- Thread: single impulse deorbit from an elliptical orbit (/thread-19139.html) single impulse deorbit from an elliptical orbit - cdeaglejr - 11-14-2022 01:45 PM This HP Program calculates the single impulsive deorbit maneuver required to establish a reentry altitude and flight path angle relative to a non-rotating, spherical Earth. The algorithm uses a tangential delta-v applied opposite to the velocity vector of an initial elliptical orbit to establish the de-orbit trajectory. The following is a "hard-wired" example with the program input in bold font. // perigee altitude (kilometers) hp := 285.798; // perigee radius (kilometers) rp := req + hp; // apogee altitude (kilometers) ha := 35785.922; // apogee radius (kilometers) ra := req + ha; // entry altitude (kilometers) hentry := 111.252; // entry flight path angle (degrees) fpae := -4.0; The software will compute and display the orbital elements of the deorbit trajectory and the magnitude of the required deorbit delta-v. The zipped archive for the software and documentation for this example can be downloaded from https://www.dropbox.com/s/2f2zxm1frqxycp8/edeorbit.zip?dl=0