In a first, a Sony CubeSat propeled itself in orbit using water vapor

Japanese firm Pale Blue flew a nano-satellite using water vapor propulsion for the first time.

The company's propulsion system, tested aboard Sony's Star Sphere 1, or EYE, satellite, passed its first test using the environmentally friendly, low-cost propellant method.

Next, the two companies will use the novel method to boost the satellite into its intended orbit.

Pale Blue aces first water propulsion CubeSat test

During the test on March 3, Pale Blue's water-based thrusters fired off for roughly two minutes. Data later confirmed that the engine's initial test was successful, the company confirmed in a press statement on Monday.

The EYE nanosatellite is Sony's first satellite for its Star Sphere project, which aims to make space photography more accessible.

EYE launched alongside 113 other satellites aboard a SpaceX Falcon 9 rocket as part of the SpaceX rideshare mission Transporter 6 on January 6. The nanosatellite, or CubeSat, features a camera and will operate from an altitude of about 310 to 372 miles (500 to 600 kilometers) above the surface of the Earth. The successful test of Pale Blue's propulsion system means it can now help the satellite maneuver to its target orbit, allowing it to begin operations later this year.

“Pale Blue successfully developed and operated its water-based thruster, and with this, the company takes a huge step forward towards orbit insertion for [Star Sphere] Project,” Jun Asakawa, CEO and Co-Founder of Pale Blue, explained in the company’s statement.

Water and light propulsion could be the future of CubeSat navigation

Pale Blue says that its water propulsion thruster was designed to prolong the life of the small EYE satellite's lifetime by 2.5 years with small periodic orbital correction maneuvers.

The company explains that water-vapor propellant is also a more environmentally friendly solution amid the growing demand for CubeSats — small satellites that require longer lifespans. The propulsion system splits water into hydrogen and oxygen while in space to burn them as fuel.

In 2019, The Planetary Society's Light Sail 2 mission showed that flight by light is also possible. The mission used a 32-square-meter (244-square-foot) sail made out of mylar to raise a small CubeSat spacecraft’s orbit by 1.9 miles (3.2 km). Essentially, all a light sail CubeSat mission needs is a similar sail to keep itself in orbit for a surprisingly long time using only the power of photons from sunlight. Lightsail technology has since been implemented into a number of NASA missions.

Now, water propulsion technology looks like it could have a similar impact, as NASA has also been testing the technology with its Pathfinder Technology Demonstrator-1 spacecraft.