UK’s SteamJet chosen for Artemis II offshoot

Unlike most other space propulsion systems, SteamJet’s Steam Thruster One uses low-pressure water as its main propellant. It produces a nominal thrust of 6mN at 20W, making it suitable for orbital adjustments and collision avoidance onboard CubeSats and small satellites. According to the start-up, using water makes it greener and safer than the high-pressure, toxic propellant systems widely relied upon by the space sector.

The technology is now set to be deployed on the K-RadCube, a satellite developed by South Korea’s NaraSpace. After launching as part of Artemis II’s payload, the CubeSat will be sent into a highly elliptical orbit to study Earth’s Van Allen radiation fields. 

K-RadCube’s first orbit will reach an apogee of approximately 70,000km and a critically low perigee that would cause the spacecraft to re-enter Earth’s atmosphere. To avoid this, the SteamJet propulsion unit will perform a continuous 12-hour burn to raise the perigee to around 200km, preventing atmospheric re-entry and allowing the satellite to carry out its scientific mission. If successful, SteamJet said the manoeuvre will represent one of the longest single burns ever conducted in orbit by a water-based propulsion system.