This is an image of Momentus' Ardor thruster for Ardoride, a multi-kilowatts propulsion system the firm is developing to power 500 to 1,000-kilogram spacecrafts. Momentus is testing the technology in its laboratory and plans to fly it for the first time in 2020.

Russian entrepreneur Mikhail Kokorich is backing Momentus, a Silicon Valley startup developing water plasma engines.

This post is only available to members.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She is a recipient...