A Review of Existing Policies Affecting the Jettison of Waste in Low Earth Orbit and Deep Space

The management of waste generated onboard spacecraft during future long-duration
deep-space missions will require different solutions from those currently implemented on the
International Space Station which consist exclusively of collecting, storing, and returning the
waste to Earth. Alternative options for managing spacecraft waste are to process it for
recycling and recovery of resources, and to jettison it overboard in a solid form (such as a
compacted tile) or in a gaseous form after torrefaction or other trash-to-gas technologies. The
waste generated during a deep-space mission is derived mainly from spacecraft logistics
supplies, food and beverage residues, personal or scientific items used by the crew, human
metabolic waste, and unused spare components. Uncontained and unprocessed trash is a
potential health hazard and a habitat volume liability, which makes onboard long-term
storage an inefficient and non-optimal option. However, the jettison of solid, processed waste
appears to be an effective solution for crewed deep-space missions, leading not only to volume
reduction and habitat safening, but also to considerable mass savings in the spacecraft’s
propulsion system. However, the disposal of trash overboard also creates a navigation hazard
for spacecraft and the potential risk of contamination of planetary bodies, interfering with the
search for life. This paper investigates the requirements covered by existing policies that could
affect the jettison concept of operations and system design.