Rocket propellant can be produced anywhere that water is found by splitting it into hydrogen and oxygen, potentially saving several tons of mass per mission and enabling the long term presence of humans in space beyond LEO. When water is split into hydrogen and oxygen, the gaseous products can be very humid (several thousand ppm). Propellant-grade gases need to be extremely dry before being converted into cryogenic liquids. The primary objective of this project is to design, build and test a regenerative gas drying system that can take humid gas from a water electrolysis system and provide dry gas to the inlet of a liquefaction system for long durations. State of the art work in this area attempted to use vacuum as a means to regenerate desiccant, but it was observed that water would migrate to the dry zone without a sweep gas present to direct the desorbed vapor. Further work attempted to use CO2 as a sweep gas, but this resulted in a corrosive carbonic acid. In order for in-situ propellant production to work, we need a way to continuously dry humid gas that addresses these issues.More »
The objective of this effort is to design, build, test and evaluate a method of gas drying that can be used for in-situ propellant production. Test data from this project will be used in models to help predict the total mass, power, and volumes associated with various ISRU applications and architectures. The final product will be a fully functional system that will be integrated into an end-to-end ISRU propellant production demonstration.More »
|Organizations Performing Work||Role||Type||Location|
|Johnson Space Center (JSC)||Lead Organization||NASA Center||Houston, TX|
|Kennedy Space Center (KSC)||Supporting Organization||NASA Center||Kennedy Space Center, FL|
Testing of the canister design verified that the product gas was below the dryness required (26 ppmv) after 4 hours of continuous use. The canister was designed to operate on a 4 hour regeneration cycle. Visual observation of the desiccant (indicating drierite) after 4 hours shows that approximately half of the desiccant became saturated. After four hours of operation, the water content at the outlet of the canister was 15 ppmv. This test validated the design of the canister, where the residence time of the gas is a
function of the canister diameter.