Orbital mobility is becoming a fundamental requirement for modern satellite missions. Until recently, a satellite was considered to be a static object. After launch, the satellite remained in its orbital position until the end of its service life. Currently, there are many factors that affect the functionality of the satellite. Namely, the growing number of satellites in orbit, the risk of collisions, and the need to manage constellations. Thus, a satellite must be able to actively manoeuvre throughout its entire mission. That is precisely why orbital mobility has gone from being a “nice bonus” to a mandatory requirement for modern missions.
In this article we are going to break down the criterion you need to consider when planning orbital mobility and provide a checklist that you can use to objectively evaluate any propulsion system.
Key Parameters for Planning Orbital Mobility
When evaluating different propulsion systems, it is important to use the same set of criteria. In this way, engineers can compare different solutions more objectively.
# | Orbital Mobility Parameter | Why It Matters |
|---|---|---|
1. | Regulatory Status (ITAR/EAR) | Determines how quickly you can launch a mission, which partners and suppliers you can work with, and whether you will face any restrictions on technology exports |
2. | Propellant Safety and Handling | Hazardous propellants require additional procedures. As a result, storage, transportation, and launch-site handling can increase both mission time and cost. |
3. | Efficiency by Weight and Volume | The key metric is how much delta-v the system provides per kilogram of its mass. The higher this metric, the less payload space has to be sacrificed. |
4. | The Complexity of Integration | How many engineering hours will be required to integrate the system into the satellite and test it? The simpler the integration, the faster and less expensive mission preparation will be. |
5. | Cost per mission | The total cost consists not only of the price of the equipment itself, but also of testing, as well as the risks covered by mission insurance. |
6. | Scalability | Can the solution work across a wide range, from a small 1U CubeSat to a large satellite in a constellation? The technology’s versatility reduces the need to seek out different solutions for different projects. |
7. | Reliability and Flight Experience | Does the technology have a proven track record: successful flights and accumulated performance data from real-world orbital operations? This reduces the risks to the mission. |
How SteamJet Propulsion Supports Orbital Mobility
The criteria provide a practical framework for evaluating any propulsion system intended to support orbital mobility. In practice, SteamJet propulsion systems can be evaluated against the same criteria.
Regulatory simplicity
SteamJet thrusters use water as a propellant, which is non-toxic and non-hazardous. Therefore, some of the ITAR restrictions are removed. On top of that, logistics during pre-launch preparations are simplified.
Weight efficiency for small platforms
The compact design allows for the system to be mounted on a CubeSat without significantly reducing payload space.
Less Complex Integration
Non-hazardous propellant reduces the requirements for safety systems and simplifies ground handling. Pre-flight preparation takes less time and fewer resources.
Cost-effectiveness at every stage of the mission
Simpler safety procedures reduce the cost of testing and qualification compared to chemical propulsion, where toxic propellants require expensive inspections.
Case Study: Longest In-Orbit Burn with Steam-Based Propulsion
A real-world mission provides a practical example of how propulsion enables orbital mobility. The Artemis II mission demonstrates how SteamJet technology can support a demanding orbital manoeuvre.
The Artemis II Mission: K-RadCube
Mission planners selected SteamJet Space Systems to become part of the Artemis II mission, the first crewed flight to the Moon in the last 50 years. The mission aimed to adjust the orbit of the South Korean K-RadCube satellite, which otherwise risked burning up in the atmosphere.
After separating from the launch vehicle, the satellite was to enter a highly elongated elliptical orbit with an apogee of about 70,000 km. However, its perigee was supposed to pass through the upper layers of Earth’s atmosphere. Without orbital corrections, the satellite would have lost altitude as early as its first orbit.
Solution: Mission engineers selected the SteamJet Thruster One to raise the satellite’s perigee to 200 km through a sustained 12-hour burn, one of the longest continuous burns that a water-fueled engine can perform in space.
Technical Details of the Manoeuvre
Parameter | Value |
|---|---|
Initial orbit | Highly elliptical, apogee ~70,000 km |
Corrective action | 12-hour thruster burn |
Purpose of the manoeuvre | Raise the perigee to ~200 km |
Thruster | SteamJet Thruster One |
Isp | More than 250 ns |
Propellant consumption | ~170 g of water (about a quarter of the water in the tanks) |
During the burn, the thruster had to operate for 12 consecutive hours without overheating or causing the satellite to exceed safe temperature limits. At the same time, it had to generate enough heat to produce the necessary thrust.
Traditionally, mission teams used chemical propellants for such manoeuvres under extreme orbital conditions.. It is expensive, toxic and difficult to handle. This case study demonstrates that water can deliver comparable performance without these risks.
Modern orbital mobility requires more than simply reaching an orbital position. Satellites need to actively manoeuvre to maintain their orbit, avoid collisions, and perform mission-specific corrections. Therefore, selecting the propulsion system became one of the key decisions in preparing for the mission.
When selecting a propulsion system, engineers should consider more than the equipment price. They should also evaluate regulatory restrictions, propellant safety, ease of integration, and flight heritage.
SteamJet meets most of these criteria thanks to a simple solution: water as a propellant. It is safe, requires no complicated storage procedures, is not subject to strict export restrictions, and is efficient enough for use on both CubeSats and larger satellites.
The example of the Artemis II mission with the K-RadCube satellite confirms this in practice. Ultimately, water is capable of performing tasks that were previously considered the exclusive domain of toxic chemical propellants.
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.