Managing Phase Change and Freezing in Water-Based CubeSat Propulsion Water

Water-based CubeSat propulsion system managing phase change and freezing in orbit

Water may seem like a perfect propellant for CubeSats and Small Sats. It offers non-toxic operation, zero launch-site hazards, low-pressure storage, and ITAR-free procurement.  For these reasons, water-based CubeSat propulsion has evolved in recent years from a novelty into a popular practical tool for small satellites.

At the same time, the use of water involves one fundamental technical aspect that must be considered. Namely, its behaviour in vacuum. At low pressure and low temperature, water approaches its triple point. Consequently, it can simultaneously exist as a liquid, vapour and ice. For the thruster, this poses a few risks. Namely, water freezing in the tank, ice forming in the lines, and unstable operation of the vaporisation chamber. Therefore, controlling these phase transitions becomes the key engineering challenge.

What Happens with Water in Space

Water reaches its triple point at 0.01 °C and 611 Pa. At lower pressures, the liquid phase is impossible. Thus, flash freezing occurs in a vacuum; a drop simultaneously boils and freezes in a fraction of a second. Moreover, thermal conditions of a CubeSat in LEO exacerbate the situation. Temperature ranges from -40°C to +60 °C. Without active thermal control, phase transitions introduce critical failure modes:

  • Structural overstressing of propellant tanks due to ice volumetric expansion (~9%).
  • Ice-plug formation in feed lines and micro-valves.
  • Thermal instability and pressure oscillations in the vaporization chamber.

However, CubeSat can not accommodate an additional heater to keep the tank warm constantly. The satellite power budget is limited. As a result, constant heating of the tank would consume power needed for the payload. One of the ways to handle propellant phase change is active continuous thermal maintenance. It means to keep the feed lines and tank permanently above 0° using continuous bus power. Unfortunately, this approach demands high bus power consumption during standby/eclipse. On a 3U or 6U CubeSat with a constrained power budget (10 – 20 W average generation), spending continuous watts on propellant thermal maintenance starves the primary payload.

Practical Approach to Phase Management

Tank Thermal Design

Engineers install an external heater on the tank. It turns on only when the thruster is operating, that is, immediately before and during a manoeuvre. The rest of the time, the heater is off, and the tank may freeze along with the propellant. This is an acceptable normal operating condition.

The key idea behind our approach is that propellant freezing is treated as a design case, not as a failure mode. Before commissioning, the propellant can freeze without any risk to the tank or the feed system. The hardware survives multiple freeze-thaw cycles during launch and early orbit operations. After commissioning, keeping the water permanently liquid is no longer a challenge to be solved by continuous heating. For missions where negative temperatures are expected, we use a water-alcohol mixture as the propellant, which lowers the freezing point and eliminates the problem at the propellant level rather than at the thermal control level. As a result, heaters are activated only when needed, shortly before a manoeuvre, instead of running around the clock.

Composition of the Working Propellant

Pure water as a propellant has a narrow stability window: it freezes as low as 0 °C, and behaves unpredictably in a vacuum due to its proximity to the triple point. For a CubeSat that regularly enters the Earth’s shadow, this poses a constant risk.

Therefore, instead of pure water, we use a water-alcohol mixture as the working propellant. The addition of alcohol significantly lowers the solution’s freezing point. This is a classic colligative effect: a solute lowers the freezing point of a liquid, the same principle by which automotive antifreeze works.

What does it mean in physics:

  • Depressed Freezing Point: Significantly lowers the freezing threshold, shifting the liquid phase boundary to withstand sub-zero orbit phases without freezing solid.
  • Mitigated Volumetric Expansion: Prevents destructive ice-lattice formation, protecting tank walls, feed lines, and valve seats from mechanical stress.
  • Vaporisation Dynamics: Alters vapour pressure and enthalpy of vaporisation, allowing rapid phase change in the heating chamber before expansion through the nozzle.
  • Impulse Performance: Maintains a competitive specific impulse Isp comparable to pure steam systems while improving system reliability

What does it mean in practice:

  • The tank and lines can easily withstand the cold sections of orbit without risk of damage;
  • Constant heating isn’t needed during pauses between manoeuvres, which saves energy for the payload;
  • Before the thruster ignites, a heating coating preheats the mixture and feeds it into the vaporisation chamber as usual.

In the chamber, the mixture vaporises and accelerates through the nozzle, providing thrust. In terms of performance, this solution is comparable to using pure water as a propellant and does not reduce the engine’s efficiency.

Mission Benefits and Technology Readiness

Once the system controls the phase transitions of water throughout the entire architecture, the freezing problem no longer exists. It becomes a standard operating procedure. In practice, this means several specific things for the mission:

  • Consistent specific impulse. The thruster behaves predictably throughout the entire mission.
  • Predictable propellant consumption. This means accurate Δv planning and confidence in completing tasks before the end of the service life.
  • The propellant’s own properties eliminate the risk of tank rupture. The water-alcohol mixture used as the operational propellant does not freeze at the temperatures encountered during the mission.
  • Ability to have extended pauses between manoeuvres without system degradation. The satellite can go months without firing its engine and still perform when needed.

In recent years, water-based CubeSat propulsion has evolved from an intriguing concept into an engineering-mature technology. Engineers not only know the challenges associated with phase transitions, they have studied them and validated the solutions in flight. Therefore, for a propulsion engineer selecting a propulsion system for a mission, water is no longer an experimental risk but a well-understood engineering domain with established solutions and predictable behaviour.

Engineering Parameter
Cold-Survival Water/Alcohol System
Traditional Monopropellant / Cold Gas
Standby Power Consumption
0 W
1 – 5 W (Constant line heating)
Storage Pressure
< 2 bar (Unpressurized launch)
High pressure (100 – 300 bar) or hazardous liquid
Launch Integration Hazard
Green / Non-Hazardous
Complex / High Safety Overhead
Cold-Storage Shelf Life
Unlimited (Immune to freezing damage)
Risk of line freezing or thermal runaway

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in water-based propulsion solutions designed specifically for CubeSats and Small Satellites (SmallSats), prioritising operational safety and rapid launch integration. 

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:

Steamjet TunaCan Thruster: A compact, high-efficiency solution for 1U-3U CubeSats.

Steamjet TunaTank Thruster: A safe, high-performance electrothermal propulsion system.

Steamjet 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.

The Evolution of CubeSat Mobility: From Passive Drifting to Active Manoeuvring

CubeSat mobility using water propulsion

Today, CubeSat mobility is a mandatory requirement for any modern mission. Ten years ago, a CubeSat was simply launched into orbit and left to drift. It relied entirely on the trajectory into which the rocket had placed it. Essentially, it was a passive object in space. Such a satellite could neither avoid a collision, nor correct its orbit, nor perform a controlled deorbiting at the end of its mission.

Space industry has changed fundamentally. So did the requirements for the mission design. Furthermore, regulatory standards became stricter. The FCC’s five-year deorbiting rule and ESA’s Zero Debris Charter have to be taken into account when planning a mission. At the same time, launch providers now deploy satellite constellations into orbit on a regular basis. All of these factors have turned controlled manoeuvrability from a useful feature into a critically important capability.

Why Small Satellites Need Active CubeSat Propulsion Systems

The lack of mobility presents engineers with several serious problems that cannot be solved after launch.

  1. Uncontrolled orbital decay. Due to atmospheric drag, the satellite gradually loses altitude.
  2. Inability to avoid collisions. Low Earth orbit is becoming increasingly crowded. Therefore, tracking networks regularly issue collision warnings. However, without a propulsion system, the manoeuvre for CubeSat collision avoidance would be impossible.
  3. Uncontrolled deorbit. At the end of the mission, the satellite re-enters the atmosphere at an unpredictable time and in an unpredictable location.
  4. Limited mission capabilities. Lack of mobility decreases the satellite’s service life. On top of that, the range of tasks it is capable of performing is significantly smaller.

The Economics of Mobility

At first glance, a propulsion system may look expense. However, after calculating the cost of not having one, it becomes obvious that it is not.

Extending the service life leads to increased return on investment

Station-keeping adds 1–3 years of active operation to a satellite. At the same time, the launch cost remains the same. Consequently, every additional month in orbit reduces the effective cost of the mission.

The investment is lost if the satellite crashes unexpectedly

To develop and launch a single CubeSat costs hundreds of thousands of dollars. If a collision happens, the investment is misspent.

Failure to comply with regulatory requirements

Without a deorbit system, the mission will not comply with mandatory regulations. As a result, all development and launch costs will be wasted.

Precise manoeuvring saves the launch costs

The satellite’s own propulsion allows operators to manoeuvre the satellite into its target orbit, if the launch provider placed it off-course.

CubeSat mobility is no longer an expense. It is a solution that protects an investment. A propulsion system turns a CubeSat into a controllable asset. It operates longer, doesn’t get lost in a collision, and is guaranteed to meet regulatory requirements. Today, the question isn’t whether you can afford a propulsion system, but whether you can afford not to have one.

Enabling CubeSat Mobility

First, understanding which types of propulsion systems are suitable for CubeSats is important to choose the right one for a mission. CubeSat propulsion guide helps to evaluate different thrusters and their parameters.

It used to be a difficult task to pick the propulsion system for CubeSat. Chemical thrusters provide good thrust but run on toxic propellant. Hence, they require complex approvals and pose risks during launch preparation. Electric thrusters are efficient. However, they are expensive and operate at high voltages. Either of these options means extra cost, extra weight, and lengthy approvals with the launch provider.

Unlike conventional propulsion systems, SteamJet thrusters use water resistojet technology and water as propellant. It is non-toxic, non-explosive, and completely safe. Our propulsion systems provide many advantages:

  • Easier launch preparation. No hazardous propellant means no lengthy safety checks or restrictions on launches.
  • Cheaper and more reliable. Water costs next to nothing, and the system itself is simpler than its chemical counterparts.
  • Safe at every stage. In addition, operators can safely store, transport, and refuel the satellite.
  • Compact. The system fits within the CubeSat’s strict weight and volume limits, leaving room for payload.

Mission Performance and Lifetime Extension

At the same time, this green satellite propulsion solution handles all the necessary tasks. Namely, positioning satellites in formation, maintaining orbit, avoiding collisions, and deorbiting within the timeframe required by the regulator.

The baseline SteamJet Thruster One configuration delivers a total impulse of 1200 Ns for a typical 3U to 12U CubeSat, or small satellites up to 100 kg. Moreover, the system is based on ITAR-free propulsion hardware, simplifying international collaboration and procurement. Depending on the deployment altitude (typically between 400 km and 600 km) and the spacecraft’s ballistic coefficient, this impulse capability translates directly into 1 to 3 years of active orbit maintenance and life extension.

Engineers once considered CubeSat mobility an expensive luxury. Today, sustainable space propulsion makes active manoeuvring accessible without introducing hazardous propellants. As a result, water removes this barrier and makes the thruster what it should be for a CubeSat — a safe, inexpensive, and essential part of the mission, rather than a source of problems.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in water-based propulsion solutions designed specifically for CubeSats and Small Satellites (SmallSats), prioritising operational safety and rapid launch integration. 

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:

Steamjet TunaCan Thruster: A compact, high-efficiency solution for 1U-3U CubeSats.

Steamjet TunaTank Thruster: A safe, high-performance electrothermal propulsion system.

Steamjet 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.

The CubeSat Propulsion Guide: Choosing the Right Thruster for Your Mission

SteamJet TunaCan water-based CubeSat thruster

The CubeSat propulsion system is a critically important component that determines the satellite’s capabilities in orbit.

Orbital mobility encompasses active collision avoidance maneuvers (CAM), station-keeping, and post-mission disposal (PMD) to comply with international mitigation standards. In fact, a satellite is just a passive object in space without a propulsion system.

The propulsion system allows for expanding the range of satellite applications. As a result, the satellite can change its orbit to perform various tasks. In addition, it can participate in formation flying and extend the mission’s lifespan.

Today, a space mission has to comply with regulatory requirements that are increasingly stricter. Current international standards, the FCC introduced a 5-year deorbit rule and the ESA Zero Debris Charter, require operators to ensure that a satellite is deorbited after the end of its mission. Therefore, without a propulsion system, adhering to the new standards is impossible.

A CubeSat loses most of its useful functions without the propulsion system. And it can’t meet the modern requirements of the space industry.

Key Parameters to Consider When Choosing CubeSat Propulsion

Several critical characteristics directly affect the success of the mission. Thus, they have to be taken into account when selecting a propulsion system.

Thrust Level

Contemporary CubeSat propulsion systems offer a wide thrust range. From micro-newtons for electric thrusters (0.1 – 5 mN) to hundreds of millinewtons for chemical propulsion systems (100 – 1,000 mN). For instance, emergency evasion manoeuvres require high thrust. On the other hand, precise positioning needs low thrust.

Δv (Velocity Change) Budget

Δv (delta-v) is the primary indicator of a satellite’s manoeuvring margin. Engineers calculate it using the Tsiolkovsky rocket equation, which depends on the thruster’s specific impulse and the satellite’s propellant mass fraction.

Response Time

The time from receiving a command to the start of the manoeuvre can range from a few seconds to hours, depending on the type of propulsion.

If an emergency happens, for example, when operators receive a collision warning 12–24 hours in advance, the system must respond rapidly. It takes minutes to activate chemical and water-based systems. Electrical systems require a lengthy warm-up period and respond slowly.

Power Consumption

Different types of thrusters necessitate varying amounts of electrical power. Electric propulsion systems demand tens of watts of continuous power for hours or days. In contrast, chemical and cold-gas systems consume minimal energy, primarily for control electronics and valve actuation. Water electrothermal systems, however, require peak electrical power during operation to vaporize and heat the propellant, though their standby power remains low. 

Size and Mass Limits

CubeSats have standardised dimensions. Therefore, every cubic centimetre counts. In general, there are two ways to house a propulsion system. The first one is to place it inside the satellite and take up valuable payload space. Second is external mounting. It is also necessary to account for the mass of the system itself and the propellant supply. Typically, it ranges from 0.5 to 3 kg for a 6U satellite, which accounts for 5–25% of the total mass.

Safety & Launch Approval

Launch service providers impose strict safety requirements on propulsion systems. Firstly, the certification process for chemical systems is complex and lengthy. This propulsion system uses toxic propellant and high storage pressures (over 100 bar). Gas systems are approved more quickly and easily due to non-toxic propellants but high pressure.Water systems are the fastest to approve as a green satellite propulsion, since the propellant is non-toxic and is contained under lowest pressure.

Cost and Development Timelines

Commercial Off-the-Shelf (COTS) space hardware  is the optimal option for many missions. Its cost is $50,000–$200,000 and can be integrated in a few months.

On the contrary, in-house development is much longer and usually increases the overall price. However, for certain missions, it is justified.

Types of CubeSat Propulsion Systems

Chemical Propulsion

High thrust (100–1,000 mN) and rapid response, which is ideal for urgent manoeuvres. However, they have a few disadvantages. Namely, high toxicity propellants (e.g., hydrazine), complex fluid handling, and rigorous launch range safety certification (e.g., AFSPCMAN 91-710). Overall, this type of propulsion system is good for major orbital changes and emergency collision avoidance manoeuvres.

Cold Gas Propulsion

Cold gas propulsion systems are safe and easy to use. However, their main disadvantage is low efficiency (Isp ~50–70 s) and a requirement for a large fuel tank. As a result, these systems work well for demonstration missions and simple short manoeuvres.

Electric Propulsion (Ion, Hall, FEEP)

This type of thrusters have a high efficiency (Isp 1,500 – 5,000 s). However, its thrust level is low (0.1–5 mN) and energy consumption is high. Moreover, these systems have a slow response; it may take hours or even days to manoeuvre. Electric propulsion is well-suited for long-term missions, orbit maintenance, and slow orbital transfers.

Water Electrothermal Propulsion (SteamJet TunaCan, TunaTank, and Thruster One)

SteamJet thrusters are completely safe because they use water as a propellant at low storage pressure. The TunaCan thruster takes up zero internal volume (0U) because it is mounted outside the satellite. The thrust level is moderate (~20 mN), which provides a balance between speed and efficiency. Our water-based thrusters for small satellites  are perfect for 3U – 16U satellites to facilitate collision avoidance, formation flying, and rapid deorbiting.

Mission Profiles: Which Propulsion System to Choose

Mission Type
Key Requirements
Recommended Propulsion
Collision Avoidance (CAM)
High thrust, fast response
(<1–5 hours)
Chemical, Water-based
Station-Keeping
Moderate Δv, frequent small burns
Electric (Ion), Water-based
Orbit Transfer
High Δv budget
Electric (long burns), Chemical (fast), Water-based (fast, moderate Δv)
Deorbiting
Compliance with deorbiting requirements
Electric (high Δv, slow descent) or Water-based / Chemical (high-thrust rapid clearance)
Formation Flying
Precise, repeatable maneuvers
Water-based , Cold Gas
Technology Demonstration
Low cost, simplicity
Cold Gas, Water-based

Choosing the right propulsion system will determine the success of the entire CubeSat mission. And the system that fits all types of missions simply doesn’t exist.

For example, chemical propulsion systems work well for emergency manoeuvres. Meanwhile, electric propulsion systems are good for long-term missions with limited propellant supplies. Finally, cold gas systems suit simple demonstration projects.

Water-based electrothermal propulsion systems, such as SteamJet (TunaCan, TunaTank, and Thruster One), offer an optimal balance for modern compact satellites. They combine safety, fast response, sufficient thrust, and a compact design that doesn’t take up internal space – a critical factor for small 3U–16U satellites.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in water-based propulsion solutions designed specifically for CubeSats and Small Satellites (SmallSats), prioritising operational safety and rapid launch integration. 

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:

SteamJet TunaCan Thruster: A compact, high-efficiency solution for 1U-3U CubeSats.

SteamJet TunaTank Thruster: A safe, high-performance electrothermal propulsion system.

SteamJet 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.

Orbital Mobility for Nanosatellite Constellations: Propulsive Response Times in Active Collision Avoidance

Water propulsion system enabling orbital mobility for small satellites

Low Earth Orbit (LEO) is no longer an empty space.  Orbital Mobility has become a critical capability for satellite constellations operating in an increasingly crowded environment. The number of satellites and space debris has grown exponentially. Therefore, for satellite constellations, the ability to quickly change course and avoid potentially dangerous close encounters is becoming increasingly important. It is especially important for nanosatellites. Hence, the decision to manoeuvre often has to be made almost immediately. Because there is usually not enough time available between the warning and a potential collision.

A 6U CubeSat typically weighs around 12 kg. Avoiding a dangerous close approach depends on orbital calculations and on how quickly it can execute a manoeuvre command, which directly defines its orbital mobility capabilities. Slow reaction or low thrust leaves almost no time. Thus, when selecting a propulsion system, it is important to consider its practical effectiveness:

  • startup speed
  • thrust reserve
  • safety
  • compliance with mission requirements

For this reason, water-propulsion systems are particularly appealing. They provide small satellites and CubeSats with manoeuvrability without unnecessary risks or complications regarding launch clearance. Further, we examine the key characteristics of a water-propulsion system and show why it could be a practical solution for orbital mobility.

Space Sustainability Standards, CAM Distance and Orbital Mobility Timeline

Satellite operators activate pre-established safety protocols when the risk of a dangerous close encounter in LEO exceeds the acceptable threshold Pc > 10-4. They assess the situation according to strict criteria:

  • Miss Distance: to avoid collision, the operator has to determine in advance how close the two objects will pass each other. Also, whether the satellite will have time to change its trajectory. At the Time of Closest Approach (TCA), the safety radius between the centres of mass of the two encountering objects must be at least 1–2 km.
  • Trajectory Displacement: the satellite doesn’t need to change the orbit; the small manoeuvre is usually enough. Operators must alter the satellite’s path by 200 to 500 meters relative to its original trajectory.
  • The Planning Window: these situations shouldn’t be resolved at the last moment. The first warnings of a possible collision usually appear a few days in advance. Approximately 3 to 7 days before TCA. Operators make the final decision on the manoeuvre closer to the event, 24–36 hours in advance. The thruster itself is usually activated 12–24 hours before a dangerous close approach, so that the satellite has time to gradually move to a safe distance.

Propulsion Comparison: Finding the Best Thruster for Orbital Mobility in Small Satellites

For a 12 kg 6U CubeSat, the time it takes for the thrust to provide the nominal velocity change for a quick evasion manoeuvre (Delta V = 0.2 m/s) depends on the type of propulsion system used. The effectiveness of each propulsion technology directly impacts orbital mobility and the ability of a spacecraft to perform timely collision avoidance maneuvers.

Propulsion Performance Overview

1. Chemical thrusters deliver the highest thrust level (~1000 mN). This thrust level enables an extremely fast response — a Δv of 0.2 m/s is achieved in just ~2.4 seconds. These systems are highly responsive in emergency windows. They are capable of reacting up to 1–2 hours before TCA. However, the trade-off is complex integration: the propellants are hazardous and highly volatile, which complicates their use in a 6U satellite.

2. Cold gas systems offer low thrust (~10–50 mN). They require 48 seconds to 4 minutes to reach a Δv of 0.2 m/s. These thrusters remain robust in emergency scenarios, responding up to 3–4 hours before TCA. Safety is their main advantage. However, they are highly inefficient and consume a large amount of internal payload volume. It is a significant drawback for compact CubeSats.

3. The SteamJet TunaCan produces ~20 mN of thrust. Our thruster delivers a Δv of 0.2 m/s in ~2 minutes. It is dependable in emergency windows, responding up to 4–5 hours before TCA. Its standout benefit is the 0U design footprint. Zero internal volume impact makes it ideal for space-constrained missions.

4. Electric propulsion (FEEP/Ion) provides the lowest thrust (~0.4–1.2 mN). This kind of thruster needs 33 minutes to 1.6 hours to reach a Δv of 0.2 m/s. As a result, FEEP/Ion systems are ineffective for late-notice or urgent threats. On top of that, it imposes a high electrical power drain, forcing slow, multi-day tracking rather than rapid maneuvers.

Chemical thrusters respond quickly to imminent collision threats. Whereas electric engines (FEEP/Ion) are too slow for emergency maneuvers. The SteamJet TunaCan system offers the best balance of safety, response speed, and internal space efficiency. And it does not take up any usable space on the satellite.

Emergency vs. Nominal Manoeuvres: The Reality of Orbital Risks

There are two categories of risk collision based on the analysis of manoeuvres in low Earth orbit. These scenarios demonstrate why orbital mobility is becoming an essential requirement for modern satellite operations.

1. Nominal/Planned Manoeuvres, 95%–97% of cases
In most of the cases, the operator receives a warning in advance. Therefore, the satellite has enough time to avoid collision. Under these conditions, high-thrust systems and water-based electrothermal thrusters produce nearly identical practical results.

2. Emergency Manoeuvres, ~3%–5% of cases
Situations like this happen when there is almost no time left to react. Several reasons may lead to these situations. For example, radar blind spots, solar activity spikes expanding the upper atmosphere, or sudden data revisions in Conjunction Data Messages (CDMs) less than 24 hours before TCA.

The TunaTank Advantage: Next-Generation Water Propulsion Technology

Although electric propulsion (FEEP) has a high specific impulse, its thrust is in the micro-newton range. Hence, it is not well-suited for rapid manoeuvres. The corrections have to be planned days in advance. On top of that, the system consumes valuable power from the onboard batteries in the process. Conversely, chemical thrusters present additional challenges. Primarily in terms of safety during storage, launch, and operation.

The TunaTank Thruster is our new water-based propulsion system. We developed it based on our experience with the TunaCan Thruster. The system supports small satellites and gives them more capabilities without unnecessary risks. In fact, TunaTank offers a perfect balance between effectiveness and safety.

  • Clean Propulsion Technology: runs on water, a non-toxic, “green” propellant stored at low pressure.
  • Space Qualified Reliability: designed according to  ESA ECSS and NASA GSFC standards.
  • Flight-Proven 3D Printing: custom printed manifolds allow the system to be adapted to the layout of a specific CubeSat.
  • Uncompromised Volume: The external scalable architecture preserves the satellite’s internal volume for the payload.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in water-based propulsion solutions designed specifically for CubeSats and Small Satellites (SmallSats), prioritising operational safety and rapid launch integration. 

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:

SteamJet TunaCan Thruster: A compact, high-efficiency solution for 1U-3U CubeSats.

SteamJet TunaTank Thruster: A safe, high-performance electrothermal propulsion system.

SteamJet 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.