A team from the U.S. space agency NASA has demonstrated the handling and loading of a Swedish-developed “green" propellant that could provide a higher-performing, safer and less-expensive alternative to hydrazine to power satellites and manned spacecraft. As part of an international agreement with the Swedish National Space Board (SNSB), the team simulated a flight-vehicle loading operation with LMP-103S Green Propellant, which NASA says "smells like glass cleaner, looks like chardonnay, but has proven powerful enough to propel a satellite."

LMP-103S "smells like glass cleaner, looks like chardonnay." Image credit: C. Perry/NASA. The demonstration took place late in 2015 and will be followed this year by additional tests. Goddard’s Propulsion Branch is carrying out a fracture test to determine the behavior of a flight tank should it crack while loaded with the propellant. And at the end of 2016, the branch plans to test fire two Swedish-developed spacecraft thrusters powered by LMP-103S.

All tests are designed to show that LMP-103S is a viable alternative to hydrazine, a toxic propellant that requires personnel to wear full-body protective gear when handling and loading the propellant into spacecraft. By comparison, engineers can handle LMP-103S wearing safety glasses and a smock.

The propellant, which Stockholm-based company ECAPS AB began developing about two decades ago with SNSB funding, is based on ammonium dinitramide, a high-energy salt. It made its debut about five years ago aboard PRISMA, a Swedish spacecraft equipped with a pair of one-Newton thrusters.

Over the years, 70 LMP-103S-powered thrusters have been built and used in different applications. NASA’s Pre-Aerosol, Clouds, and Ocean Ecosystem mission also is investigating using LMP-103S-powered thrusters.

Although hydrazine will not be completely displaced due to its long-term and widespread use, the green propellant potentially offers advantages. In addition to being easier to handle, it is more tolerant of low temperatures and could bring about less-expensive, more flexible mission designs. Further, if it proves to be higher performing than hydrazine, spacecraft could carry out more maneuvers on one tank of propellant or could reduce the amount of propellant needed, leaving room for additional instruments or experiments.