Engineering topics
Publications and source records attributed to Glass, A. B..
Monte Carlo Investigation of Trajectory Operations and Requirements (MONITOR) program performs spacecraft mission maneuver simulations for craft mission maneuver simulations for geosynchronous single-maneuver, and cometencounter trajectories. Used primarily to study geosynchronous missions and model trajectories of satellites deployed by Space Shuttle. Program written in FORTRAN IV.
Control of the trajectory and attitude for the International Sun-Earth Explorer-3 (ISEE-3) spacecraft is performed using an onboard hydrazine propulsion system. This paper describes the spacecraft hardware and operational limitations that were considered in the planning, execution, and evaluation of all ISEE-3 maneuvers performed to date. Propulsion system performance and spacecraft dynamics models as implemented in the maneuver support computer software are described. Examples are presented that show how maneuver goals are achieved while satisfying mission orbit and attitude constraints. Procedures used in the development of maneuver plans are detailed for the second midcourse correction maneuver which typifies maneuver operations in general.
The applications sensors of many low altitude earth satellites designed for recording surface or atmospheric data require near zero orbital eccentricities for maximum usefulness. Coverage patterns and altitude profiles require specified values of orbit semimajor axis. Certain initial combinations of semimajor axis, eccentricity, and argument of perigee can produce a so called 'frozen orbit' and minimum altitude variation which enhances sensor coverage. This paper develops information on frozen orbits and minimum altitude variation for all inclinations, generalizing previous results. In the altitude regions where most of these satellites function (between 200 and 1000 kilometers) strong atmospheric drag effects influence the evolution of the initial orbits. Active orbital maneuver control techniques to correct evolution of orbit parameters while minimizing the frequency of maneuvers are presented. The paper presents the application of theoretical techniques for control of near frozen orbits and expands upon the methods useful for simultaneously targeting several inplane orbital parameters. The applications of these techniques are illustrated by performance results from the Atmosphere Explorer (AE-3 and -5) missions and in preflight maneuver analysis and plans for the Seasat Oceanographic Satellite.