Water-fueled thruster successfully raises orbit.

Momentus has successfully demonstrated the propulsion system on its Vigoride space tug, raising the vehicle’s orbit using its Microwave Electrothermal Thruster (MET). The MET vaporizes water with microwaves to generate thrust and has fired for more than 140 minutes cumulatively, in burns ranging from 30 seconds to six minutes each. The company said that those burns raised the orbit of Vigoride-5 by more than three kilometers when taking atmospheric drag into account. The test of the MET is a major milestone for Momentus, which is relying on the technology to propel its tugs that will deliver satellites to their desired orbits.