Fuelling the satellite is a very important step in the mission. This process directly affects whether the satellite will function properly in space.
However, this process is often complicated and demands strict safety regulations. In particular, when the toxic substances are used. For CubeSats and small satellites, this stage becomes even more delicate due to limited resources and compact design.
In contrast, water propulsion simplifies the fueling procedure. It makes the process easier and safer than other traditional approaches.
Challenges of Satellite Fuelling
Traditional propellants make the fuelling process more complicated and demanding.
Toxic propellants
Hazardous chemical components are often used and must be handled with great caution.
Specialized conditions
Fueling takes place in designated areas equipped with systems to monitor environmental conditions and pressure, as well as personnel safety measures.
Complex logistics
Toxic fuel has to be stored, transported, and prepared. All of this requires additional resources.
Technical personnel
The personnel must be trained, certified, and experienced in handling hazardous components.
The fuelling process becomes expensive, long, and complicated, especially for small satellites. That is precisely why there is a growing focus on simpler and safer solutions, such as water propulsion.
What Is Water Propulsion for CubeSats
Water propulsion is a type of propulsion system that uses water as a propellant. The operating principle is simple. First, the system heats the water. Then, the water turns into steam. As the steam exits, it generates thrust. As a result, this approach is considered to be a safe alternative.
Fuelling a CubeSat with Water Propulsion
Water significantly simplifies the fueling process compared to other options. First, engineers prepare the propulsion system. Next, they fill the tank with water. After that, they perform a leak test.
In the final stage, the system is integrated into the satellite and prepared for launch. Overall, this process involves fewer steps. It is also safer and easier to manage.
The diagram shows how Thruster One is fuelled with water. The fuel is stored in a tank connected to a scale and is fed into Thruster One. Nitrogen from the cylinder creates pressure in the tank, causing the fuel to flow through the line via Valve 3 and the Schrader valve into the engine. The scale indicates how much fuel has been dispensed from the tank, so it is used to monitor the refueling volume. When the required amount of fuel has been delivered, the valves close and refueling stops.
Benefits of On-Site Fuelling with Water Propulsion
- Safety
Water is not a toxic component, thus fuelling becomes much safer for people and equipment. - Simplicity
The fuelling system is simple and doesn’t demand any specialized procedures or conditions. - Non-hazardous
There is no need to handle hazardous chemicals, which reduces safety requirements. - On-site fuelling
Refueling can be performed directly at the customer’s laboratory, without the need for specialized facilities.
The main advantage is that there is no hazardous handling: no need to work with hazardous substances, which means fewer risks and a simpler process overall.
All of this is particularly important for CubeSat missions:
Speeds up launch — fewer complex procedures, faster preparation
Reduces costs — no need for expensive systems or handling hazardous materials
Simplifies integration — easier to integrate the system into a satellite
Fewer barriers for customers — no specialized infrastructure or complex preparation required
Ultimately, water propulsion offers a simpler and more flexible approach to launching satellites and makes space missions more accessible.
About SteamJet Space Systems
SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in water-based thrusters designed specifically for CubeSats and Small Satellites (SmallSats), with a strong focus on water-based thruster safety.
By pioneering the use of green propellants and intelligent thermal engineering, SteamJet enables complex LEO (Low Earth Orbit) manoeuvres — including orbital maintenance, collision avoidance, and de-orbiting — without the risks associated with toxic hydrazine or high-pressure cold gas systems, advancing green propulsion for space missions.
Steamjet Propulsion Technology
Our modular systems are engineered for seamless integration and maximum safety compliance:
Steam TunaCan Thruster: A compact, high-efficiency solution for 1U-3U CubeSats.
Steam Thruster One: Scalable propulsion for larger SmallSat constellations.
Discover how SteamJet’s sustainable space propulsion innovations are providing the safety and reliability required for the next generation of crewed and robotic missions. Contact our engineering team for technical specifications and ICDs.