Accession Number:

AD0855389

Title:

Minimum-Fuel Thrust-Limited Transfer Trajectories Between Coplanar Elliptic Orbits.

Descriptive Note:

Technical rept.,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s):

Report Date:

1968-12-01

Pagination or Media Count:

175.0

Abstract:

A method is developed for the efficient computation of minimum-fuel transfer trajectories between coplanar elliptic orbits with a thrust-limited variable-mass rocket moving in a central gravitation force field. Each orbit is defined through the eccentricity, semi-latus rectum, and argument of pericenter. Transfer time is left open. The minimum-fuel trajectory is assumed to consist of two thrusting phases separated by a coasting phase. Computation of the minimum-fuel transfer trajectory is accomplished by a direct integration of the rocket equations of motion and the associated adjoint equations which are developed from variational calculus techniques. This direct approach is made possible by a unique transformation of the adjoint equations into a set of equations which provide a much better understanding of the general behavior of minimum-fuel transfer trajectories. Reasonable estimates of the thrusting interval durations, initial thrust angle, and initial true anomaly are derived from the corresponding minimum-fuel, two-impulse transfer trajectory. The initial value of a newly discovered variable is used in conjunction with the initial thrust angle to obtain the thrusting interval durations specified by the two-impulse transfer. Author

Subject Categories:

  • Unmanned Spacecraft
  • Spacecraft Trajectories and Reentry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE