On Earth, gravity draws liquid to the bottom of a tank. In space, low gravity lets propellant cling to the walls, making the amount harder to judge. NASA’s Radio Frequency Mass Gauge uses radio waves and antennas inside a tank to estimate what remains; the agency says the estimate is not an exact measurement. [S1]
For the people planning a mission, the estimate matters both for deciding how much propellant to launch with and for making the most of mission duration, according to NASA’s Lauren Ameen. The agency developed the gauge at its Glenn Research Center in Cleveland and planned to fly it on Intuitive Machines’ IM-1 lunar delivery through its Commercial Lunar Payload Services initiative. [S1]
NASA says the planned flight would be the gauge’s first long-duration test on a standalone spacecraft, following smaller experiments on the International Space Station and during parabolic flights. Data received by engineers during the journey could help validate ground simulations, the agency says. [S1]
The technology could be useful for future long-duration missions using cryogenic propellants such as liquid hydrogen, oxygen or methane, NASA says. Those propellants can evaporate quickly even at low temperatures, making them difficult to store. [S1]
Source documents
- NASA Tests New Spacecraft Propellant Gauge on Lunar Landerhttps://www.nasa.gov/centers-and-facilities/glenn/nasa-tests-new-spacecraft-propellant-gauge-on-lunar-lander/