Pale Blue is a Japanese startup developing innovative water-based thrusters and green propulsion systems for satellites.
Founded in 2020 by researchers from the University of Tokyo, Pale Blue Inc. (HQ in Kashiwa, Japan) pioneers safe and sustainable spacecraft propulsion. Its patented micro-thrusters use water as a propellant, employing miniaturized electrostatic and electrospray technology to deliver high-efficiency thrust for CubeSats and microsatellites. By exploiting water (the 'pale blue' element), the company aims to reduce the toxicity and cost of conventional propulsion systems like hydrazine or xenon. Pale Blue’s product lineup (such as the PBR series) targets satellite attitude control, orbit maintenance and station-keeping. The firm has secured venture funding (Series A/B/C) and plans on-orbit demonstrations including a water Ion thruster test on a D-Orbit launch in 2025. Its technology appeals to Earth observation and commercial satellite operators seeking green propulsion alternatives.