Spacecraft Formation Flight in Unstable Orbital Environments

Professor Daniel Scheeres

Department of Aerospace Engineering

University of Michigan


The dynamics and control of multiple spacecraft in proximity to each other is an emerging area of interest to the astrodynamics community. Possible applications of such spacecraft formations include space-based long-baseline interferometry, the simultaneous monitoring of space environments over large regions, and control of satellite constellations. For interferometric imaging of nearby stars and their (possible) planetary systems, spacecraft formations travelling in halo orbits about the Earth-Sun $L_2$ libration points have been proposed. The dynamics and control of spacecraft formations in such orbits are inherently interesting as these regions of phase space have positive Lyapunov Characteristic Exponents (i.e., are unstable). This has a number of strong implications for the mapping of spacecraft uncertainty and the control of relative motion for a formation of spacecraft.

This talk will review orbit dynamics in the vicinity of halo orbits and give a brief elucidation of some interesting aspects of this problem. Then, a new approach to stabilizing relative motion between spacecraft in this environment, a fundamental issue for formation flight, will be presented.


Friday, April 6, 2001

3:30 - 5:00 p.m.

1500 EECS