Mitsubishi: Investing in Water-Powered Satellite Tech
Since 2022, Mitsubishi has been running an accelerator fund for startups in the tech space.
Pale Blue, a small Tokyo-based company, has captured the imagination of the ME Innovation Fund's judges in 2025 thanks to its water-powered propulsion systems designed for satellites.
Typically, satellites are powered by hydrazine, a toxic chemical that is dangerous to work with.
By using a highly-advanced water propulsion system, Pale Blue is able to make the preparation and deployment of satellites safer, more cost effective and less damaging to the environment.
Pale Blue's unique satellite technology
Pale Blue’s advanced satellite propulsion technology might appear complex at a glance, but its principle is straightforward.
In the simplest possible terms, Pale Blue's system uses water as the primary fuel for thrust, meaning its only emissions are safe and non-reactive.
This development not only promotes safety in space operations but also sets a new benchmark for eco-conscious satellite technology.
The startup was founded in 2020 as a spinout from the University of Tokyo, an academic institution that famed for its development of sustainable technologies in recent years, such as a form of dissolvable plastic created in collaboration with RIKEN.
So far, Pale Blue has completed multiple in-orbit demonstrations using small satellites.
This road testing has attracted investors including Sony and now Mitsubishi.
These tests have helped to validate the reliability of the technology and the firm is now ready to scale up its production, which it now plans to use its external investments to do.
Is there a demand for sustainable space technologies?
Over the past decade, the satellite industry has experienced huge growth, with constellation deployments across commercial and public sectors in high demand.
Propulsion is something that all satellites need for positioning, orbital transfers and mission operations.
Making that technology less dangerous, less expensive and less carbon intensive is therefore a natural development.
"At Pale Blue, we aim to contribute to the expansion of activity in space by providing mobility – that is, the capability to move freely in space – through our propulsion systems," explains Jun Asakawa, the company's Co-Founder and CEO.
The investment makes sense for Mitsubishi with a space business that operates across satellite manufacturing, ground systems and related technologies.
"Pale Blue possesses the potential to realise safety, efficiency and environmental compatibility in space transportation through its innovative water-based propulsion technology," says Komi Matsubara, Executive Officer at Mitsubishi Electric.
"Such sustainable propulsion solutions are essential for the future of space infrastructure and are closely aligned with the direction of our space business."
Mitsubishi's Role in Scaling Green Innovation
As a fuel, water has a lot of theoretical advantages over conventional propellants.
Be that as it may, water-based systems typically generate lower thrust levels compared to chemical alternatives, potentially limiting their applications.
The technology may prove most suitable for smaller satellites requiring precise manoeuvring rather than large orbital transfers.
Market adoption will likely depend on demonstrating competitive performance metrics alongside the sustainability benefits.
