Pale Blue designs, develops, and manufactures propulsion systems for small satellites, having demonstrated water‑based thrusters in space multiple times. The company was founded in 2020 and is headquartered in Kashiwa, Chiba. Its core product line focuses on reliable, scalable thrusters for global satellite operators, and it is expanding its portfolio to include Hall thrusters. Pale Blue plans to strengthen production and quality-management systems, establish a production‑technology development site, and scale hiring to meet growing demand. The company will continue R&D and space demonstrations to broaden its product lineup and validate new propulsion technologies. The recent Series C fundraise will support these commercialization and production efforts. Pale Blue is a University of Tokyo–spawned space startup based in Kashiwa, Chiba that researches, develops, and manufactures propulsion systems for small satellites. Its core products are an ultra‑small water ion thruster and a water Hall thruster, both using water as the propellant. The ultra‑small water ion thruster is an electric propulsion system for orbit control and orbital transfers offering higher fuel efficiency than chemical thrusters; the water Hall thruster uses a water‑Hall plasma acceleration effect to achieve high specific impulse with low power consumption. These thrusters are intended for small‑satellite orbit control and attitude control. Pale Blue aims to reduce small‑satellite operating costs, expand launch opportunities, and ultimately apply its technology to deep‑space missions such as lunar or Martian exploration. The company plans to continue development and manufacturing, pursue in‑space demonstrations, establish a production‑technology development base, and strengthen its organization. Pale Blue is a Tokyo-based small-satellite thruster developer focused on water-based propulsion, notably its Resistojet steam thruster. The company tested its Resistojet in orbit in March on a 6U cubesat called Star Sphere, using jets of steam for maneuvering. Pale Blue is building a 2,000-square-meter factory to mass-produce Resistojet thrusters sized for satellites under 10 kilograms and announced $7.5 million in funding in October to start production for customers including Yonsei University. Under a multiphase Japanese government SBIR-3 grant worth up to $27 million, Pale Blue aims to develop water-plasma propulsion and to scale its technology to service spacecraft up to 500 kilograms. The company plans to demonstrate water-fed ion and Hall-effect thrusters, which use electricity and magnetic fields to accelerate propellant, with a demo targeted around 2027–2028 and prototypes due by September 2025 for the first grant phase. Pale Blue positions water as a lower-cost, safer propellant alternative to xenon, though it acknowledges water cannot yet match xenon's thrust performance.

Total raised

$53M

Funding rounds

3

Latest round

Series C

Latest activity

Aug 2025