Inside the Sustainable Satellite Technology Mitsubishi Funds

Since 2022, Mitsubishi has been running an accelerator fund for innovative start-ups in the tech sphere. This year's recipient is about to go stratospheric.

Pale Blue, a small Tokyo-based company, captured the imagination of the ME Innovation Fund's judges, 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.

The details of Pale Blue's satellite technology

Pale Blue's satellite technology can be hard for the uninitiated to wrap their heads around. It combines low-pressure, ambient-temperature water vaporisation with low-power plasma generation that resists oxidation.

In the simplest possible terms, Pale Blue's system uses water as the primary fuel for thrust, meaning that its only emissions are safe and non-reactive.

The start-up 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 naturally been very attractive to investors, with Sony, another major Japanese tech firm, investing before 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?

In 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, whose space business 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."

What are the commercial prospects of this technology?

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.

How Mitsubishi can propel this technology skyward

The investment reflects growing corporate interest in sustainable space technologies as the industry grapples with orbital debris concerns and environmental considerations.

Traditional satellite propulsion relies on toxic chemicals that pose handling risks and environmental challenges.

Water-based alternatives could reduce these concerns whilst potentially lowering operational costs.

"Through collaboration with Mitsubishi Electric, we will further enhance the reliability of our technology and work toward realizing our vision of establishing mobility as a core element of the space industry," Jun says.

The partnership combines Pale Blue's innovative propulsion technology with Mitsubishi's established space systems expertise and manufacturing capabilities.

Financial terms of the investment were not disclosed, consistent with typical practice for corporate venture investments at this stage.