Future space transportation requirements for the management of orbital debris

Launch vehicle upper stages continue to contribute to future orbital debris scenarios whenever they undergo explosive propulsion system failures, as well as by remaining on orbit as potential collision targets for smaller orbiting bodies. No active measures have been instituted to date in order to remove nonfunctional satellites or spent rocket stages from earth orbit; they are nevertheless conceivable, and classifiable as (1) orbital-maneuvering retrieval; (2) self-disposal; and (3) propulsive deorbit or atmospheric drag augmentation. Illustrative cases and parametric assessments of these methods' feasibility and cost are presented.