Most modern CubeSat propulsion systems are designed to be compact and provide basic functionality. However, when the mission becomes more complicated, it is the propulsion system that begins to limit the satellite’s capabilities.
Firstly, it is the low thrust, which leads to slow maneuvers and reduced orbital control. Secondly, the volume of propellant is constrained. Every centimeter counts when it comes to CubeSats. Standard propellant tanks take up useful space that could have been used for payload. As a result, less propellant is carried — and the mission becomes shorter or less flexible.
This creates the need for a compromise. Either more propellant and better maneuverability, or more payload. Conventional solutions do not allow both objectives to be achieved simultaneously. Consequently, the design becomes more complicated, and the missions become less efficient.
TunaTank: A New Approach to CubeSat Propulsion
TunaTank is a new kind of propulsion system for CubeSats. It resolves the main issues with the traditional systems. TunaTank provides better capabilities without increasing the satellite’s size through its semi-external design.
The propulsion system is divided into two parts. The tank is located inside the satellite, taking up the free space that usually remains available. And the thruster itself is placed within the deployer — the so-called tunacan. This design allows for efficient use of space.
Unlike customary CubeSat propulsion systems, TunaTank does not require choosing between propellant volume and payload. It helps to store more propellant and keep the useful space inside without sacrificing the thrust power.
Essentially, it is a novel approach to design. Instead of trying to operate within the constraints, it utilizes all available space, inside and out, to expand the mission’s capabilities.
Flexible Tank Design Without Membranes
TunaTank has a 3D-printed tank without a membrane. This significantly improves the design flexibility. It is possible to create a custom-printed tank for a specific satellite. Thus, the shape, internal layout, and mission objectives are taken into account.
The system itself is divided into two parts. A single unit, the so-called “head”, is mounted on the outside. It includes the control system, heat exchanger, valves, and filling assembly. This block is installed within the deployer.
Only the tank is inside the satellite. It may be printed in almost any shape to ensure that the available space is filled as efficiently as possible.
It is also important to note that this technology has already been put to the test and has proven to be reliable and effective in operation.
Unlocking New Opportunities for CubeSat Missions
TunaTank allows for utilizing available space in the most efficient way, instead of enduring the limitations. It leads to faster maneuvers, more propellant, and improved flexibility in terms of mission control. The satellite may operate longer, perform complicated tasks, and adapt to changes in the orbit.
At the same time, the integration process becomes simpler. There is no need for a complicated fuelling process and working with toxic substances. As a result, reduced costs and fewer potential risks.
TunaTank lowers the barriers to entry and makes more complex missions accessible. Thus, it opens up new opportunities to scale up CubeSat missions.
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.