Minimum-fuel aeroassisted coplanar orbit transfer using lift-modulation
Abstract
Minimum-fuel trajectories and lift controls are computed for aeroassisted coplanar transfer from high orbit to low orbit. The optimal aeroassisted transfer requires less fuel than the all-propulsive Hohmann transfer for a wide range of high orbit to low orbit transfers. The optimal control program for the atmospheric portion of the transfer is to fly at maximum positive L/D initially to recover from the downward plunge, and then, to fly at negative L/D to level off the flight, such that the vehicle skips out of the atmosphere with a flight path angle near zero degrees. To avoid excessive heating rates, the vehicle flies initially at high angle of attack in order to slow down higher in the atmosphere, allowing recovery from the downward plunge, which occurs subsequently using the maximum positive L/D, to take place at a lower atmospheric density, or equivalently, at a higher altitude.
- Publication:
-
Atmospheric Flight Mechanics Conference
- Pub Date:
- August 1983
- Bibcode:
- 1983atfm.confR....M
- Keywords:
-
- Computer Programs;
- Fuel Consumption;
- Lift Drag Ratio;
- Optimal Control;
- Trajectory Control;
- Transfer Orbits;
- Angle Of Attack;
- Coplanarity;
- Equations Of Motion;
- Flight Paths;
- Trajectory Optimization;
- Astrodynamics