The Future of Orbital Sustainability: ISRU for the New Space Economy

Water propulsion system supporting the future space economy and ISRU infrastructure

The space industry changes rapidly. The “new space” sector is making missions more frequent, commercial, and decentralized. More small satellites are being launched into orbit, and new services are emerging. On top of that, there is a growing interest in lunar and near-lunar infrastructure.

However, sustainable space development demands more than just reducing launch costs. Consequently, the future space economy requires efficient logistics. Future missions must deliver, store, and utilise resources in space without constant dependence on Earth.

In-Situ Resource Utilisation (ISRU) plays a major role in the future of space exploration. This approach reduces the need for propellant delivery, water, and other resources from Earth.

Water is one of the most valuable resources. Besides supporting life, it can also power CubeSat propulsion systems, provide radiation shielding, and enable future near-lunar logistics. Hence, water is an important element that helps to develop ISRU, sustainable orbital infrastructure, and new space missions.

What ISRU Means for the New Space Economy

In simple terms, ISRU means using the resources that exist in space rather than bringing them from Earth. The new space economy is going to benefit greatly from ISRU. Furthermore, the more missions there are in orbit, near the Moon, and in deep space, the more difficult and expensive it will be to continuously send all the necessary supplies from Earth. In-Situ Resource Utilisation will help to build a more independent and sustainable space infrastructure.

Furthermore, national programs such as the Luxembourg Space Resources initiative also show that space resources are becoming an important part of the future commercial space economy.

Resource
Moon
Asteroids
Mars
Cislunar / Orbit
Water ice
Medium
Medium
High
Future supply
Oxygen
High
Medium
High
Future supply
Regolith
High
High
High
Limited
Metals
Medium
High
Medium
Limited
Solar energy
High
High
Medium
High

In addition, ESA also highlights the importance of lunar resources and materials, including regolith, oxygen and other materials that could support future exploration infrastructure.

Why Water is the Ultimate Strategic Resource for ISRU

Water is one of the most important resources for future space infrastructure. Unlike many other types of propellant, water is safe and convenient in terms of storage. As a result, water becomes an excellent choice for long-term missions and orbital services.

For example, in space, water can serve several purposes at once. Namely, propulsion systems, radiation shielding, thermal control, and crew life support.

Scientists have found water ice on the Moon and may find it on other celestial bodies. If future missions extract and process it on site, water could become part of future ISRU supply chains. Consequently, for near-lunar and deep-space missions, water can become an important logistical commodity. It will be possible to extract, store, transport, and use it wherever it is needed to support space infrastructure.

Water-Based Propulsion is a Step Toward Sustainable Mobility

Water-based propulsion systems are an efficient solution for small satellites and CubeSats. Water as a propellant is much safer than traditional types of propellant. As a result, integration, testing, transportation, and preparation are simplified.

In the future, water electrothermal thrusters will fit perfectly into the ISRU supply chains. Eventually, future missions could use extracted and stored water not only to support life but also to power the orbital mobility of satellites and other spacecraft.

Scaling from SmallSat Constellations to Cislunar Infrastructure

Today, propulsion systems enable CubeSats and small satellites to perform low Earth orbit (LEO) manoeuvres, adjusting their orbit, and managing the mission flexibly. Looking ahead, the next step is in-orbit mobility. In this environment, water-based propulsion systems are useful for orbital servicing, satellite inspection, rendezvous, collision avoidance, and the management of satellite constellations.

In the future, future missions could use water obtained through ISRU for refuelling and logistics in near-lunar space. This will make it possible to build a more sustainable infrastructure connecting Earth, the Moon, and other destinations.

Thus, water propulsion serves as a bridge between today’s small satellites and the space infrastructure of the future.

Combining Water Propulsion and 3D Printing for Space Mobility

The SteamJet propulsion system bridges the gap between water-based green propellant technology and additive manufacturing. By utilising 3D printing, we can manufacture highly compact, safe, and custom-shaped thruster components tailored for modern small satellites. As a result, additive manufacturing minimises total dry mass, simplifies assembly, and maximises layout flexibility within tight CubeSat form factors.

“Our strategic goal is to bring our sustainable propulsion systems to the Moon, asteroids, and beyond,” states Marco Pavan, CEO of SteamJet Space Systems. “Water propulsion technology is the foundation required to build an independent, efficient, and truly sustainable space infrastructure.”

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:

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

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

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.

Modular Propulsion: Optimizing CubeSat Volume Efficiency with Custom Tanks

CubeSat propulsion system with custom titanium propellant tank by SteamJet

Engineers often consider thrust, specific impulse, system mass, and total impulse when selecting a propulsion system for CubeSat. NASA’s Small Spacecraft Technology State of the Art report demonstrates that these are the key factors for small spacecraft propulsion systems. However, small satellites have another limitation that, in most cases, becomes the major one. Namely, the internal volume.

In simple terms, volume efficiency refers to how effectively the system utilizes the available space inside the satellite. If more propellant can be stored within the same CubeSat dimensions, the spacecraft gains additional maneuvering capability without increasing its external size.

As a result, this directly affects mission capability. If other parameters are unchanged, a larger usable propellant mass can increase the available ΔV margin. As a result, the satellite can support additional orbit adjustments, unscheduled maneuvers, extended mission duration, or end-of-life deorbit.

Therefore, engineers should evaluate not only the thruster parameters, but also how efficiently the propulsion system uses the satellite’s internal volume. A well-integrated fuel tank can enhance a mission’s capabilities even without modifying the engine itself.

Why Cold Gas Systems Limit CubeSat Volume Efficiency

In cold gas propulsion systems, the propellant remains in a pressurised gaseous state. The tank becomes a high-pressure container, rendering its geometric profile critical for uniform stress distribution and structural integrity under high pressure. Simple shapes, such as spheres or cylinders, are usually the most efficient for this type of tank. They distribute internal pressure better and help reduce structural risks.

However, for a CubeSat, it presents a design challenge. The interior of a satellite is typically rectangular and tightly packed with other systems, so a spherical tank does not fit well in such a space. There are empty spaces left around the tank that are impossible to use for payload, electronics, and additional propellant storage. Thus, even if a cold gas propulsion system fits well in terms of the thrust and the mass, its tank may be using the internal volume inefficiently.

Unpressurized Propellant Gives More Freedom in Tank Design

In SteamJet thrusters, the propellant is not stored under high pressure. Hence, engineers can design the tank in a wider range of shapes than in cold gas propulsion systems. This removes one of the main geometric constraints. A tank does not have to be spherical or cylindrical.

Instead, our engineers adapt tanks to the available space inside a CubeSat or Small Satellite. If there is an irregularly shaped space inside the unit, it is no longer a “dead space” but an additional propellant storage capacity.

Titanium Additive Manufacturing Enables Complex Tank Geometry

We use titanium direct metal laser sintering (DMLS) to manufacture tanks. It allows the production of tanks with complex shapes that are difficult or impossible to manufacture using traditional methods. Instead of adapting the satellite’s internal layout to fit a standard tank, the tank can be designed to fit a specific available space inside the satellite.

This is especially important for CubeSats and Small Satellites, where every centimeter counts. After electronics, payload, and other systems have been installed, the tank can be 3D-printed to match the space as precisely as possible. As a result, the satellite may carry more propellant without increasing its size.

Patented Tank Architecture Supports Сonformal Propellant Tanks for Small Satellites

Our patented tank design enables the engine to operate with tanks of various shapes, not just standard ones. This is important because the capability to 3D-print the tank doesn’t solve the issue. The thruster has to receive a steady supply of propellant and function properly with this configuration. The tank that may be adapted to the internal volume of the CubeSat or Small Satellite gives engineers greater flexibility when integrating the propulsion system.

More Usable Propellant Volume Without Increasing CubeSat Size

The custom tank’s main advantage is its capability to increase the volume of propellant without increasing the size of the CubeSat. It can replicate the available geometry inside the satellite. As a result, the custom tank converts more of the internal space into usable propellant capacity rather than remaining as “dead volume”.

For the mission, it means:

  • greater flexibility for orbit adjustments;
  • longer operational lifespan;
  • additional margin for unforeseen maneuvers;
  • the ability to perform deorbit at the end of the mission.

The deorbiting process is no longer optional. At the moment, it is a prerequisite. The FCC introduced a 5-year deorbit rule for LEO satellites, while ESA promotes sustainable mission design through its ESA Zero Debris Charter.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialise in green water propulsion for CubeSats  and Small Satellites (SmallSats), with a strong focus on 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 TunaTank Thruster: A safe, high-performance electrothermal propulsion system.

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.

Proactive Collision Avoidance: How Higher Thrust Water Systems Save Assets

SteamJet water propulsion thruster for satellite collision avoidance in laboratory environment

Space debris has become a prominent issue in orbit, along with the growing number of satellites launched on a regular basis. Old satellites, fragments left by collisions, and uncontrolled objects are increasing. Collision avoidance becomes an essential part of planning to ensure the safety of the mission. Even a minor collision can result in the loss of the satellite and the creation of new debris in orbit.

Satellite loss leads to financial setbacks, missing data, mission failure, service disruptions, and other risks for the company. That is why thrusters play a bigger role these days. Modern propulsion systems not only maintain the orbit but also deliver rapid and effective maneuvers for collision avoidance. They protect the satellite and help to save the mission.

Why Low-Thrust Propulsion Systems Limit Collision Avoidance Capabilities

Many propulsion systems for small satellites are designed to be small and consume little energy. However, these systems have a major drawback, namely, low thrust.

For the purpose of collision avoidance, it becomes a problem. More time is required to perform the maneuver if the thrust is low. As a result, the opportunity to prevent potentially dangerous situations is lost.

This is particularly important during conjunction events. The situations in which there is a risk of collision with another object in orbit. Low-thrust propulsion systems face serious complications:

  • orbit correction happens too slowly;
  • the window of opportunity for the maneuver becomes longer;
  • operators have less flexibility for decision-making.

On top of that, slow maneuvers extend the workload on the mission team. The situation has to be monitored, trajectories recalculated, and any uncertainties taken into account by specialists. All of these factors complicate mission control and increase risks.

Higher Thrust Water Propulsion for Faster Collision Avoidance Maneuvers

One of the solutions for the collision avoidance is higher thrust water propulsion systems. These thrusters allow for faster maneuvers. They respond more effectively to potential threats in orbit.

In these systems, water is used as a propellant, offering several important advantages over traditional chemical alternatives. Firstly, water is non-toxic, which means that handling and operating the propulsion unit becomes easier and safer for mission teams. Secondly, satellite storage, transportation, and refueling procedures require fewer safety constraints. The integration process is also more straightforward, reducing overall operational complexity.

High thrust is one of the main advantages of these systems. It allows for quick orbit change and reduction of the time required to perform the maneuver. Higher thrust systems are essential when the collision warning is issued too late. If the propulsion system’s response is swift, the likelihood of safely avoiding a collision without significantly impacting the mission is greater.

Low-Thrust vs Higher thrust Systems for Collision Avoidance

Parameter
Low-Thrust System
Higher Thrust Water System
Maneuver response time
Slow
Much faster
Orbit correction speed
Limited
Rapid
Flexibility during conjunction events
Lower
Higher
Collision avoidance efficiency
Moderate
High
Operational complexity
Higher
Lower
Propellant safety
Depends on propellant
Non-toxic water
Integration constraints
More restrictive
Simpler integration
End-of-life deorbit capability
Limited
Supported

Operational Advantages of Water Propulsion Beyond Collision Avoidance

Collision avoidance is not the only benefit of water propulsion systems. They provide the satellite with enhanced functionality for effective operations during the entire mission.

  1. Improved orbit control for the satellite. Operators can perform necessary corrections more quickly and precisely to maintain the correct position.
  2. Refined flexibility in managing satellite constellations. This is particularly significant for constellations where it is necessary to coordinate a large number of satellites in orbit.

Furthermore, the same propulsion system may be used for collision avoidance and end-of-life controlled deorbit. This reduces the number of systems on board and simplifies the satellite’s design. Also, operational complexity is decreased compared to hazardous propellants. Since water is non-toxic, the processes involved in its preparation, transportation, and use require fewer restrictions and safety measures.

Collision avoidance becomes the standard requirement for modern satellite missions. Rapid maneuverability is a major benefit for operators and allows for mitigating in-orbit risks. Higher thrust water propulsion systems enable more effective satellite protection, ensuring mission stability and simplifying operational processes.

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:

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.

Bi-Propellant Chemical Propulsion for Small Satellites

water-based propulsion system for small satellites using safe propellant

Benefits, Challenges, and Alternatives

A bi-propellant chemical propulsion is a system that utilizes two components  – fuel and oxidizer. Once they come into contact, the ignition occurs and delivers thrust.

This type of thruster is often used for satellites and in deep space. They are used for maneuvers and orbit correction.

Bi-propellant chemical thrusters are a solution that is used often because they can generate high thrust and respond quickly. These characteristics make them indispensable for complex and precise space missions.

What Is a Bi-Propellant Chemical Propulsion?

Unlike other types of thrusters, bi-propellant chemical thrusters use two different components. In the hypergolic case,two separate propellants are injected into the combustion chamber, where they react and ignite. As a result, the chemical reaction generates high-temperature and high-pressure gas. Non-hypergolic propellants require dedicated spark-ignition hardware, which adds mass and software complexity to the CubeSat bus, or catalytic system to ignite.

The term “bi-propellant” refers precisely to the use of two components (bi = two): fuel and oxidizer. This allows for greater thrust compared to other types of engines.

Hydrazine and monomethylhydrazine are the most common propellants. Nitrogen tetroxide is usually utilized as an oxidizer. These components are very effective and produce a powerful thrust. However, they are toxic and require strict storage and handling conditions.

Currently, there are safer propellant options. For example, nitrous oxide and propene. They are less toxic and easier to handle. It allows for the reduction of the risks and costs of the missions. These propellants are much better suited for small satellites. While these alternatives reduce toxicity risks, they shift the engineering burden toward high-pressure fluid management and complex thermal conditioning to prevent phase changes in the feed lines.

How Bi-Propellant Chemical Thrusters Work

bi-propellant chemical propulsion diagram showing fuel and oxidizer interaction

This type of thruster operates due to the precise interaction of the two components. Propellant and oxidizer must be stored separately and delivered into the combustion chamber at the right moment. Valves regulate the flow and ensure the correct ratio for effective combustion.

This configuration allows for high power output and rapid changes in thrust, but requires a complex design and precise system control.

Advantages of Bi-Propellant Thrusters

Bi-propellant chemical thrusters are valued for their high power and reliability:

  • High thrust
    These thrusters are capable of generating high thrust in a short time. It is important for complicated and energy-demanding maneuvers.
  • Quick response
    The system turns on and off rapidly to guarantee the precise control of the thrust.
  • Perfect for maneuvering
    Orbit correction and other complex applications in space.

Limitations of Bi-Propellant Thrusters

Despite their high power, bi-propellant thrusters have significant limitations. Especially when it comes to the small satellites.

  • Toxic propellants
    The components used for combustion are dangerous for people and require strict safety measures.
  • Complicated storage system
    Propellant and oxidizer have to be stored separately. Also, it is important to maintain pressure and temperature, which makes the design more sophisticated.
  • Thermal Management
    For CubeSats, the structural interface must act as a thermal break to protect the bus electronics  from “thermal soakback”, and the software must include “thermal wait” periods between pulses to allow for heat dissipation.
  • High cost
    Due to their complex systems and safety requirements, these thrusters are expensive.
  • Safety challenges
    Toxic components increase risks at all the operating stages.
  • Sophisticated integration
    Installation of this kind of thruster requires more resources and time, particularly for small satellites.

Bi-propellant thrusters are not the most convenient solution for CubeSats and small satellites, where simplicity, safety, and affordability are of the utmost importance.

Bi-Propellant vs Other Propulsion Systems

There are various types of propulsion systems available today.

The monopropellant system utilizes one component, the design is simpler, but the thrust is not as powerful.

Cold gas propulsion is the least complicated system. It is safe and reliable, but the efficiency is low.

Water-based propulsion is a modern and safe solution. Instead of toxic propellant, it uses water. Thus, it is easier to store and suits well for CubeSats and small satellites.

Bi-Propellant vs Water-Based Propulsion

Parameter
Bi-Propellant
Water-Based
Propellant
Toxic chemicals
Water
Complexity
Very high
Low
Safety
Low
High
Cost
High
Low
Integration
Complex
Simple

When to Choose a Bi-Propellant Thruster

Bi-propellant chemical thrusters are a powerful and effective solution, however they are not versatile. This system works well for large satellites and sophisticated missions that demand high thrust and rapid response. Although, for small satellites it usually turns out to be too complicated, expensive, and demanding in terms of safety concerns. If simplicity, low cost, safe operation, and quick integration are crucial for the mission, it is better to consider other alternatives.

When Water-Based Propulsion Is a Better Choice

Compact size and simple operations are vital for CubeSats and small satellites. Water-based propulsion systems are much easier to integrate, hence it is usually more suitable for missions that have limited resources. Water-based systems, like those from SteamJet, offer superior “volumetric specific impulse” because water can be stored unpressurized in conformally shaped tanks.

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.

Hall-effect Thruster: Electric Propulsion for CubeSats and Small Satellites

Thruster One in the foil

A Hall thruster, or Hall-effect thruster, is a type of electric propulsion system often used in space for satellite navigation. It generates thrust by accelerating charged particles, typically xenon.

This type of thruster is usually utilized for various tasks:

  • CubeSat and small satellite missions in deep space
  • orbit correction
  • station keeping

Hall-effect thrusters are among the most widely used electric propulsion technologies. Its effectiveness and stability make it suitable for long-duration space missions.

What Is a Hall-effect Thruster?

A Hall-effect thruster is an electric thruster that doesn’t burn fuel, but functions due to the acceleration of charged particles (ions).

The operating principle is based on electric thrust. A radial magnetic field traps electrons that ionize the propellant inside the thruster. After that, these positive ions are accelerated with electric and magnetic fields, creating thrust.

The name “Hall” is connected to the Hall effect. It is a physics phenomenon that helps to control electrons in the thruster, which in turn makes the acceleration process more efficient.

How Hall-effect Thrusters Work

Hall Thruster Scheme: Step-by-Step Electric Propulsion Process

Advantages of Hall Thrusters

Hall-effect thrusters have several important advantages:

  • High efficiency specific impulse. These thrusters use less propellant compared to other types. Thus, they can operate longer with the same amount of propellant.
  • Stable thrust. These thrusters provide stable and predictable thrust, which is crucial for precise maneuvering in space.
  • Suitable for long-duration missions. Due to its stability and efficiency, these thrusters are well prepared to perform in missions that last months and even years.

Limitations of Hall Thrusters

Although hall-effect thrusters are very efficient, they too have a number of limitations. Especially when it comes to CubeSats and small satellites.

  • Xenon is an expensive gas that is not easy to store and transport in space.
  • A complicated system to inject the propellant, which makes the design more sophisticated.
  • Over time, the thruster’s internal walls wear out due to channel erosion. It shortens the service life.
  • This type of thruster demands significant electric resources that are not always available in small satellites.
  • Not always suitable for CubeSats.

Alternatives to Hall-effect Thrusters

There are various propulsion systems that create thrust in space.

Cold gas – simple systems that release gas. It is safe, but low efficiency.

Chemical propulsion – traditional propulsion systems. They are powerful, but expensive and complicated for small satellites.

Ion thrusters – electric systems similar to Hall-effect thrusters. These types of thrusters are effective; they demand advanced equipment and rare gases.

Water-based propulsion – a safe and available alternative. They use water instead of xenon; they are easier to store and work well for CubeSats and small satellites.

Water-Based Thrusters vs Hall Thrusters

Parameter
Hall Thruster
Water-Based Thruster
Propellant
Xenon
Water
Complexity
High
Lower
Cost
High
Low
Safety
Moderate
High
Storage
Complex
Simple

Hall-effect thrusters are well-suited for high-power missions that demand high thrust. Also, deep space and long-duration missions, where the thruster is expected to perform for months and even years.

Water-based thrusters are especially compatible with CubeSats and small satellites. They are perfect for cost-sensitive missions that require rapid deployment and simplicity in operations.

Hall-effect thrusters are powerful, but complicated and expensive thrusters. The space electric propulsion market is evolving, with an increasing focus on simpler and more affordable solutions. Water-based propulsion is a practical alternative, especially for small satellites and CubeSats.

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 (link) for technical specifications and ICDs.

From Lab to Orbit: Achieving Mission Assurance in CubeSat Propulsion

Mission assurance in CubeSat propulsion system testing and validation

Today, CubeSat technology is becoming more and more sophisticated. The cost of making a mistake in orbit is as high as ever, because these errors are often impossible to correct. That’s why building in mission assurance from the start is essential for keeping operations reliable, safe, and predictable. Especially so in the case of subsystems like propulsion. SteamJet delivers not just hardware, but dependable, mission-ready performance.

Successful testing on Earth doesn’t always guarantee that the propulsion system will provide the same performance in orbit. In space, the thruster is subjected to extreme temperatures, fluctuating pressure, and prolonged continuous stress. Frequently, many propulsion systems fail not because of the design, but due to the lack of a well-defined operational framework across the entire mission.

Engineering Mission Assurance from Day One

At SteamJet, we not only verify the system during the final testing, but also ensure to build in the mission reliability from the very start of the development. We follow ECSS standards and NASA’s Fault Management principles to develop our engineering solutions.

Traceability, Repeatability, and Validation

This is how we make sure that all decisions can be traced and the results can be reproduced. We continue validation at every stage. We don’t “test” reliability, we build it in from the start.

Fault Management: The Core of Mission Assurance

FDIR  (Fault Detection, Isolation, and Recovery) is a key process to provide reliability. It is especially important for CubeSats, because of the limited resources and the lack of constant monitoring from Earth, the system must be capable of responding autonomously to abnormal situations.

SteamJet thrusters are designed to “think” through anomalies. Using a sophisticated Fault Management (FM) architecture, we map out scenarios like thermal rises or pressure leaks to ensure rapid recovery.

At the fault detection stage, the system monitors telemetry parameters in real time. Namely, pressure, temperature, and more. The main goal is to identify discrepancies right away. The next stage is isolation. At this stage, we identify what exactly happened. And if it was a temporary sensor malfunction or an actual hardware problem. A false alarm may lead to an unnecessary mission shutdown.

The final stage is recovery. At this stage, the system turns back to the safe mode. It allows for adjusting operating parameters and reducing the load to maintain operational capabilities.

The Result: Predictable and Reliable Propulsion

By aligning with the NASA Fault Management Handbook, we guarantee a high level of mission assurance. As a result, the client not only receives a thruster itself, but a predictable and controllable part of the satellite that doesn’t create additional risks for the missions. SteamJet propulsion systems guarantee stable performance, resilience to malfunctions, and predictable behavior in orbit, even under the most challenging conditions.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialize 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) maneuvers — 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.

SteamJet Thruster One: Testing and Flight Readiness for Artemis II Mission

SteamJet Thruster One

SteamJet Thruster One will perform an orbit correction for South Korea’s K-Rad Cube satellite during the upcoming Artemis II mission. South Korean NaraSpace designed and built the K-Rad Cube satellite for NASA’s historic Artemis II mission, the first crewed lunar mission in over 50 years.

Once deployed into a highly elliptical orbit, the satellite will face an immediate challenge because its first perigee passes through Earth’s upper atmosphere. SteamJet Thruster One will provide the orbital correction required to prevent the satellite’s re-entry into the atmosphere.

Before any mission, SteamJet thrusters undergo a meticulous testing process to guarantee performance and reliability. Fuel tank burst pressure testing was also completed to meet the elevated safety standards required for the crewed Artemis II mission.

In addition to burst testing, engineers conducted acceptance testing on the SteamJet Thruster One for Artemis II, following established industry practices. Acceptance test campaign consists of several phases:

  • Functional test
  • Vibration dynamic test
  • Thermal vacuum test
  • Leak rate

Functional test

Functional testing verifies the thruster’s performance in all operational modes. The flight profile details all settings relevant for in-orbit operation aboard the satellite. For the Artemis II mission there are two main operational modes: commissioning and thrust.

The commissioning mode is the first operational state activated post-launch. It purges residual gases from the fuel lines.

For the Artemis II mission the thruster was optimized to deliver high thrust, operating nearly in continuous mode. This configuration ensures the mission objective is met, raising the orbit perigee to over 180 km during the first orbit.

An impulse of 240 Ns was generated in order to accomplish this goal. The test consisted of a sequence of cycles that included thrust generation, heating without firing and system health checks.  The manoeuvre was split in two parts, with a cooling period in between.

Telemetry data of a firing block:

Telemetry data of a firing block

The results of the overall functional thrust mode test are as follows:

  • Water Tanks initial condition: 350g of water on each tank at a pressure of 3.4 atm
  • Water consumed: 167.0 g
  • Total Impulse: 240 – 260 Ns
  • Thrust: 15 – 17 mN
  • Test duration: 11h 25m (including cool down period)

Vibration dynamic test

During the vibration dynamic test, engineers simulate operational conditions to ensure all components meet quality standards.

The vibration stand main specifications were the following:

Parameter
Value
Stand
ETS_L620M.std
Maximum payload weight [kg]
300.0
Reduced mass of the moving system [kg]
6.0
Operating frequency range [Hz]
3.00 – 3500.00
Buoyancy force [N]
6000.00
Maximum speed [m/s]
1.80
Maximum movement [mm]
25.00
Maximum acceleration [m/s2]
980.00

Thruster mounting for vibrations testing along X,Y,Z:

Thruster mounting for vibrations testing

During and after vibration dynamic testing, all thruster parameters remained within normal limits and met specifications.

Thermal vacuum test

The main goal of the thermal vacuum test is to check that the thruster performs and survives extreme temperatures encountered in space. Additionally, the test reveals any hidden issues early, reducing the chance of problems during the first hours of flight.

Engineers successfully completed all functional checks at the different dwell temperatures. The total mass loss during Thermal Vacuum was 0.7g, or 0.059 %, which confirms that the integrity of the thruster is maintained.

Leak rate

After the thermal vacuum test, engineers measured the leak rate. The thruster was fuelled and left for 20 hours in vacuum conditions while monitoring pressure and temperature values. Engineers detected no leaks during this 20-hour period.

Thruster telemetry during leak rate test:

Thruster telemetry during leak rate test

Conclusion

SteamJet Thruster One has successfully completed all testing required for the Artemis II mission. Functional, vibration, thermal vacuum, and leak rate tests confirmed that the thruster performs reliably in all operational modes, maintains its integrity under extreme conditions, and meets mission requirements. With verified performance and no detected leaks, the thruster is fully flight-ready to perform the critical orbital correction for the K-Rad Cube satellite.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialize 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) maneuvers — including orbital maintenance, collision avoidance, and de-orbiting — without the risks of toxic hydrazine or high-pressure cold gas systems. This approach advances 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.

Fuel Tank Burst Pressure Testing for Artemis II Mission Qualification

tank burst test

Spacecraft Propulsion Safety for a Crewed Artemis II Mission

Tank burst safety is a critical requirement for crewed space missions. For Artemis II mission, SteamJet Space Systems is preparing to demonstrate spacecraft propulsion capabilities by performing an in-orbit correction for South Korea’s K-RadCube satellite. As a result, this manoeuvre is designed to prevent premature atmospheric re-entry and relies on a simple principle: using water as the propellant.

Artemis II Mission Safety Requirements

Artemis II is a manned mission; therefore, safety and reliability are imperative. Every element of the propulsion system must withstand conditions well beyond nominal operation. In particular, the pressurised, space-grade propellant tank must safely tolerate extreme internal pressures. This capability is a critical factor for CubeSat safety and crewed mission compatibility.

For this reason, the SteamJet team performed fuel tank burst pressure testing last year to confirm that the pressurized tank meets the Design Burst Pressure requirement defined in ANSI/AIAA S-080A-2018, Section 10.4.10, as part of CubeSat mission qualification.

Why Fuel Tank Burst Testing Is Required

A fuel tank must demonstrate compliance with a burst factor (BF) of 2.5. In this case, the maximum Design Pressure (MDP) is 5.67 bar. Therefore, the required design burst pressure (DBP) is calculated as 2.5 times MDP, which results in 14.18 bar.

Design Burst Pressure = BF x ECF x MDP = 2.5 x 1.0 x 5.67 = 14.18 bar

Test Environmental Conditions

The test was conducted near ambient temperature, approximately 20°C. As a result, the environmental correction factor (ECF) remained 1.0.

During the test, pressure increased progressively at a controlled rate. This approach prevented transient load spikes or dynamic effects, thereby ensuring representative water-based thruster safety conditions.

Tank Burst Test Setup

The team positioned the pressurised tank inside a safe container to protect against shrapnel or fluid jetting in the event of rupture. Next, they connected it to a water pump designed to exceed the required burst pressure through pressure-rated fittings and hoses. Pressure gauges and sensors continuously monitored the internal pressure. In addition, temperature sensors monitored ambient conditions. The team placed them near the tank, which is consistent with space-grade propellant tank testing practices.

Instrumentation and Monitoring

The team checked the system for leaks and functionality in advance and then filled it with water. After that, all instrumentation connected to a data acquisition system for continuous monitoring and recording throughout the test. 

Because the electronic pressure sensor was limited to 30 bar, the team monitored higher pressure levels using an analogue gauge. A schematic of the test setup is shown below.

fuel tank burst testing setup

Tank Burst Test Procedure

The test began with a leak check at 5.67 bar to confirm the system was secure. Pressure was then gradually increased until it reached the calculated Design Burst Pressure of 14.18 bar. At this stage, the team held the pressure for about two minutes to verify tank integrity in line with CubeSat safety requirements.

Because the digital sensor could only measure up to 30 bar, it was removed, and the system was depressurised before continuing with the analogue gauge. Afterwards, pressure increased steadily until the tank burst. The team recorded the exact burst pressure, along with time, temperature, and the location and type of failure. Throughout the test, the team continuously monitored the system and logged all data from a safe distance.

fuel tank

Failure Location and Structural Behaviour

The tank was first pressurised up to 30 bar without rupture. After depressurisation and removal of the digital pressure sensors, the team re-pressurised the tank in a continuous event. The tank burst at 90 bar. Notably, this observed burst pressure far exceeds the required design burst pressure of 14.18 bar.

As a result, the test confirmed that the fuel tank is capable of exceeding the minimum requirement with a substantial margin, supporting CubeSat mission qualification and crewed mission safety.

tank burst test

Failure Mode and Stress Concentration

The failure happened along the edge of the tank, where stress concentrations are highest. It is consistent with the results of stress analysis. The tank edges and the centers of the smaller faces are the key areas of stress concentration.

Parameter
Required (DBP)
Actual Result
Safety Margin
Pressure (bar)
14.18 bar
90 bar
~ 6.3x
Standard
ANSI/AIAA S-080A-2018
Compliant
–
Temperature
20°C (Ambient)
20°C
–

In conclusion, the design burst pressure of 14.18 was successfully verified. The final burst pressure recorded was 90 bar. Therefore, the results demonstrate an excellent safety margin of the tank design for space-grade propellant tanks used in green propulsion systems.

About SteamJet Space Systems

SteamJet Space Systems is a leading UK-based provider of high-performance satellite propulsion solutions. We specialize 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) maneuvers — 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:

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.

Longest In-Orbit Burn with Steam-Based Propulsion Set for Artemis II CubeSat

SteamJet space propulsion system

SteamJet Space Systems will demonstrate spacecraft propulsion during the upcoming Artemis II mission with an orbiting correction for South Korea’s K-RadCube satellite to prevent its re-entry into the atmosphere. The manoeuvre uses a straightforward application of water.

K-Rad Cube satellite, developed by South Korean NaraSpace, will be onboard NASA’s historic Artemis II mission, the first manned lunar mission in over 50 years. The CubeSat will face a challenge after it is deployed into a highly elliptical orbit. Its first perigee is within Earth’s upper atmosphere. Without orbital correction, the satellite will be lost.

That’s where SteamJet’s water thruster steps in.

“This mission is about demonstrating what water-based propulsion can do in high-stakes, real-world conditions,” said Marco Pavan, CEO of SteamJet Space Systems. “We’re performing a high-thrust, high-precision manoeuvre that was once reserved for chemical systems.”

Configuring the thruster to operate safely and efficiently over the prolonged burn presented one of the mission’s key challenges. For this reason, the team had to ensure the engine would not overheat. At the same time, the satellite needed to remain within safe temperature limits. In addition, sufficient heat was required to generate the needed thrust. All systems had to remain stable and operate smoothly for approximately 12 hours.

Mission Objective

The primary mission of the K-RadCube is to monitor cosmic radiation and analyse its effects on astronauts as it passes through the Van Allen radiation belts, located more than 1,000 kilometres above Earth. However, to extend its mission duration and avoid atmospheric re-entry after the first orbit, the satellite must raise its perigee to 200 km.

To achieve this, SteamJet’s spacecraft propulsion system will conduct a prolonged 12-hour burn, one of the longest single burns ever performed by a water-based thruster in space. The manoeuvre is intended to extend the operational mission lifespan.

Key Mission Parameters:

Launch Orbit: Highly elliptical, ~70,000 km apogee

Corrective Action: 12-hour prolonged burn to raise perigee to ~200 km

Propulsion System: SteamJet Thruster One (water-powered)

According to our calculations, the thruster will deliver more than 250 Ns of impulse, corresponding to roughly 170 g of water — about a quarter of the capacity of our tanks. As a result, a significant propellant margin remains for the mission.

SteamJet Water Thruster Powers Critical Artemis II CubeSat Maneuver

Redefining the Frontiers of Green Propulsion

Previously, CubeSats that operate in these harsh environments would have required chemical propulsion — a costly, toxic, and complex solution. In contrast, SteamJet’s spacecraft propulsion technology offers the same performance without the hazards, a scalable option for deep-space and high-energy orbit missions.

Overall, the mission is a demonstration of sustainable propulsion for demanding orbit applications, enabling future CubeSats to conduct complex missions that were not possible without sacrificing safety or sustainability.

About SteamJet Space Systems

SteamJet Space Systems is a UK-based space propulsion company offering high-performance, water-based thrusters for CubeSats and Small Satellites. By utilising green propellants and intelligent engineering, SteamJet enables complex in-space missions without resorting to toxic or high-pressure systems.

Detailed technical specifications, test data, and CAD models for the Steam Thruster One are available on the website. Discover how SteamJet innovations are shaping the future of sustainable satellite propulsion.

Sustainability: Innovation and Space Debris Management

CubeSat propulsion system reducing space debris

Today, the space sector is advancing rapidly. The number of launches and satellites in orbit is increasing. This creates fresh opportunities for commerce, research, and environmental monitoring. However, this growth also brings sustainability challenges — both on Earth and in space. One of the issues is a growing amount of orbital debris being generated. Therefore, it highlights the importance of CubeSat propulsion in reducing space debris and improving orbital sustainability.

The Space Debris Challenge

Space exploration is becoming more attainable for entrepreneurs and innovators. Furthermore, with the expansion of satellite constellations in both quantity and scale, numerous new items are being introduced into low Earth orbit—not only satellites but also space debris. This debris typically includes non-functional satellites and abandoned rocket stages. As a result, orbital overcrowding and long-term viability are growing concerns.

The space debris poses a threat of collision events and may ultimately hinder or render it unfeasible for satellites to function properly in the low Earth orbits utilized for scientific purposes and communications.

Commitment to Sustainable CubeSat Propulsion

At SteamJet, we believe the future depends on making responsible choices and exploring the stars without leaving unnecessary marks. To support this goal, our commitment is to adopt sustainable and eco-friendly propellants to reduce the effect on space environments.

SteamJet propulsion systems function solely in the space environment and pose no threat to the Earth’s atmosphere. They don’t contain hazardous or flammable materials that require special care when being installed on a satellite. Additionally, our engines activate solely in space, and unlike various other satellite types, they can be deployed from a spacecraft or space station. Their launch and functioning pose no risk to the crew.

CubeSat propulsion systems powered with water transform the modern approach to satellite mobility and help mitigate space debris in orbit. Moreover, they offer safe, cost-efficient, and environmentally responsible solutions. In particular, these systems enable precise orbit adjustments, maintain satellite positioning, support constellation coordination, and ensure end-of-life de-orbiting.

More technical information regarding the thrusters is available on our website. This includes specifications, performance data, and recent test results. Steam TunaCan Thruster and Steam Thruster One. Discover how SteamJet innovations are shaping the future of sustainable satellite propulsion.