Standards for Impure Propellants

In Situ Resource Utilization (ISRU) is at the forefront of near-term lunar and Martian missions.nbsp; While many technologies and program strategies focus in ISRU, propellant production substantially impacts the scope and duration of these missions.nbsp; Through ISRU, missions can benefit from substantial mass savings, and size reduction which, in turn, result in longer durations and larger payloads.nbsp; Moreover, reusable landers within situ propellant production can reduce cost and benefit critical functions such as life support, energy storage, and scientific payloads.With the potential benefit comes certain technical challenges.nbsp; While pure methane is a well-characterized propellant, impurities that may be present in in situ production can cause a variety of issues.nbsp; Beginning in the manufacturing process, the presence of carbon dioxide, carbon monoxide, and water can affect the success of liquefaction processes.nbsp; Carbon dioxide and water both have freezing points above the saturation temperature of methane that could cause the build up of solids in liquefaction plumbing.nbsp; Moreover, carbon monoxide has a lower saturated temperature so it may either, not condense and cause gas pocket, or condense and boil off later.nbsp; It may require a conditioning stage to separate carbon monoxide from methane or maintaining temperatures low enough to keep it from boiling.nbsp;In this effort GTL proposes to determine the effect of impure propellant on mission critical systems, including storage, pressurization systems, thermal management systems, and combustion instability.