OPTIMUM THREE-DIMENSIONAL DEORBIT FOR SPECIFIC REENTRY ANGLE FROM CIRCULAR ORBITS,
Abstract
The minimum impulsive velocity requirements for three-dimensional deorbits from circular orbits to achieve any specified reentry angle are analyzed. The investigation treats two cases: the first case determines the optimum impulsive velocity for a given reentry angle and a given heading angle change; the second treats the problem of a given reentry angle and a given earth central cross-range angle. Comparisons are made between a solution based on superposition and the analytical optimum solution developed for the case of constant heading change. The method of superposition treats separately the velocity required for in-plane deorbit and the velocity required for heading change. The results are summed algebraically or vectorially to give the combined velocity requirement. It is shown that large savings may be realized by combining the deorbit impulse and the impulse necessary to change the heading angle. Moreover, the three-dimensional optimum solution may be approximated very closely by superposition provided that the corresponding two-dimensional optimum solution is used and that it is summed vectorially with correct angular relation to the out-of-plane velocity component. Finally, the parametric results of the optimum solutions for deorbit from altitudes of 75, 100, 200, and 300 n mi and reentry angles between -1 and -25 deg are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0663710
Entities
People
- S. T. Chu
Organizations
- The Aerospace Corporation