Orbital stability and other considerations for U.S. Government guidelines on post-mission disposal of space structures

During 1997, the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD), in coordination with other United States Government agencies, developed draft guidelines for debris minimization. This paper reviews the guidelines for post-mission disposal of space structures in the regimes of low Earth orbit (LEO), semisynchronous orbit (SSO), and geostationary Earth orbit (GEO) as well as the special cases of Molniya and geotransfer orbits (GTO). The cost-effectiveness of reentry and disposal orbit strategies is discussed in terms of propellant requirements, and the long-term stability of identified disposal zones is analyzed. In particular, disposal orbits near SSO are found to exhibit instabilities that could cause disposed structures to penetrate operational altitudes within 20 years of disposal. Requirements for SSO disposal orbits are proposed in light of the stability analysis. Studies of GEO disposal orbits are included for completeness.