Japan developing water based satellite propulsion system

In a groundbreaking move, Japan has taken a significant step towards sustainable space exploration by funding the development of water-based satellite propulsion technology. Tokyo-based startup Pale Blue has been awarded a grant worth up to $27 million to enhance its innovative propulsion system for larger spacecraft.

The Innovation Behind Pale Blue’s Technology
Pale Blue, a company that spun out of the University of Tokyo, has been at the forefront of developing eco-friendly propulsion systems. Their technology utilizes water as a propellant, a safer and more affordable alternative to the commonly used Xenon gas in ion and Hall effect thrusters.

The company’s Resistojet thruster, which uses jets of steam to maneuver satellites, was successfully tested in orbit in March 2023. This test marked a significant milestone, demonstrating the viability of steam-based propulsion for small 6U cubesats.

With the new funding, Pale Blue aims to scale its technology for spacecraft weighing up to 500 kilograms. The grant, part of Japan’s Small and Business Innovation Research 3 (SBIR-3) program, will support the development of water-plasma propulsion systems that leverage electricity and magnetic fields to accelerate propellant and improve efficiency.

Pale Blue’s vision extends beyond resistojets. They are working on a more advanced ion thruster system that atomizes water via a microwave plasma source. This hybrid system combines the strong thrust of the jet mechanism with the specific impulse of the ion thrust system, potentially revolutionizing how satellites maneuver in space.

Water-based propulsion offers numerous advantages. It is inherently safer to handle than traditional propellants and reduces the environmental impact of space missions. As space traffic increases, the importance of sustainable and safe propulsion systems becomes paramount to ensure the long-term viability of space exploration.