Running on Ice: The cold chain goes to space

NASA is pushing the boundaries of cryogenic technology with a groundbreaking test at its Marshall Space Flight Center in Huntsville, Alabama. Dubbed “Stay Cool: NASA Tests Innovative Technique for Super Cold Fuel Storage,” the project aims to achieve zero‑boiloff storage of liquid hydrogen by deploying a novel two‑stage active cooling system, offering a lifeline to future long‑duration missions to the Moon, Mars, and beyond.

The challenge is deceptively simple: keep liquid hydrogen boiling at roughly −424 °F. Cold long enough to prevent boiloff caused by solar heating, spacecraft exhaust, and onboard systems. The NASA article explains, “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.” 

To combat this, NASA engineers have developed a “tube‑on‑tank” method, in which chilled helium circulates through tubes affixed directly to the outer wall of the propellant tank. A multi‑layer insulation blanket, including a thin aluminum heat shield, surrounds the tank; a second layer of helium tubing carrying fluid at about −298 °F intercepts incoming heat before it reaches the tank, reducing the load on the inner system.

“Technologies for reducing propellant loss must be implemented for successful long‑duration missions to deep space like the Moon and Mars,” said Kathy Henkel, acting manager of NASA’s Cryogenic Fluid Management Portfolio Project. “Two‑stage cooling prevents propellant loss and successfully allows for long‑term storage of propellants whether in transit or on the surface of a planetary body.”