In the vacuum of space, where temperatures can plunge to minus 455 degrees Fahrenheit, it might seem like keeping things cold would be easy. But the reality is more complex for preserving ultra-cold fluid propellants – or fuel – that can easily overheat from onboard systems, solar radiation, and spacecraft exhaust. The solution is a method called cryogenic fluid management, a suite of technologies that stores, transfers, and measures super cold fluids for the surface of the Moon, Mars, and future long-duration spaceflight missions.
Super cold, or cryogenic, fluids like liquid hydrogen and liquid oxygen are the most common propellants for space exploration. Despite its chilling environment, space has a “hot” effect on these propellants because of their low boiling points – about minus 424 degrees Fahrenheit for liquid hydrogen and about minus 298 for liquid oxygen – putting them at risk of boiloff.
In a first-of-its-kind demonstration, teams at NASA’s Marshall Space Flight Center in Huntsville, Alabama, are testing an innovative approach to achieve zero boiloff storage of liquid hydrogen using two stages of active cooling which could prevent the loss of valuable propellant.