Today, Low Earth Orbit (LEO) density has reached a tipping point where orbital mobility is no longer an optional feature – it is a critical driver of mission viability, launch availability, and lifecycle cost. With thousands of operational assets creating daily conjunction risks, a static spacecraft introduces unacceptable operational and financial liabilities.
As a result, active orbital mobility – the ability to perform controlled maneuvers throughout a spacecraft’s operational life – transforms a passive payload into an adaptable, resilient asset.
Why Orbital Mobility Is a Baseline Engineering Requirement
Propulsion integration is now driven by three key operational forcing functions:
Regulatory Compliance
Currently, space agencies and national regulators are imposing increasingly strict requirements for the active management of satellites at the end of their service life. The FCC rule states that a satellite be removed from orbit within five years after the completion of its mission. Similarly, the ESA Zero Debris Charter sets a new goal to eliminate production of new space debris during routine operations by 2030. Furthermore, the UN Guidelines on the Long-Term Sustainability of Space Activities (UN LTS Guidelines) establish these principles at the international level. Ultimately, all these documents share a single requirement: a satellite must be capable of leaving orbit in a controlled manner, rather than simply waiting for natural decay.
Launch & Operational Agility
Consequently, rideshare deployments rarely place spacecraft in optimal operational planes. On-board propulsion enables rapid orbit correction, constellation phasing, and active Collision Avoidance Maneuvers (COLA).
Launch Manifesting & Time-to-Orbit
Additionally, unpressurized, non-toxic propulsion systems streamline range safety hazards, simplify launch broker approvals, and accelerate primary payload co-manifesting sign-offs.
Orbital mobility has gone from being a “nice-to-have” to an “absolute must” for any serious mission.
Technical Misconceptions in CubeSat & SmallSat Propulsion
Although the topic of orbital mobility is actively discussed in the industry, there are still quite a few myths surrounding it.
1. "CubeSat Envelopes Cannot Accommodate Meaningful Delta V Budgets"
A standard 1U to 12U envelope can accommodate a Delta V capacity of 50-150 m/s. This budget is sufficient for post-rideshare dispersion correction, constellation phasing, drag-makeup altitude maintenance, and active EOL disposal.
2. "Electric Propulsion Is Always the Superior Solution"
While Electric Propulsion (EP) provides high specific impulse Isp, its sub-millinewton thrust levels demand extensive burn durations and heavy power allocations. This constrains payload duty cycles and renders EP unsuitable for time-critical maneuvers like sudden COLA. High-thrust-to-power electrothermal water systems offer immediate impulse delivery without depleting power budgets.
3. "A Passive or Single-Use Deorbit Device Is Sufficient"
Single-use deorbit mechanisms provide no utility during primary operational phases. They cannot perform active collision avoidance, correct launch dispersion, or support orbit adjustments. A fully integrated electrothermal propulsion system provides operational flexibility across the entire lifecycle before executing final disposal.
4. "Propulsion Systems Introduce High Risk and Integration Costs"
Legacy systems required hypergolic propellants or high-pressure gas storage (>200 bar), triggering complex range safety requirements and ground handling protocols. Modern water-based electrothermal systems store propellant as an unpressurized liquid, eliminating hazardous ground operations and lowering launch integration risk.
Engineering Advantages of Water-Based Electrothermal Propulsion
Water-based electrothermal systems combine high volumetric impulse density with low integration overhead:
Safety and Ease of Integration
Stored as an unpressurized, non-toxic, non-explosive liquid, water simplifies launch site loading, hazard analyses, and co-manifesting sign-offs.
Export Control Compliance
In addition, water-based solutions are not subject to the U.S. ITAR export controls, which opens up access to the international market and simplifies working with customers around the world.
Volumetric Efficiency
Furthermore, dense liquid storage maximizes stored propellant mass within tight CubeSat envelopes without requiring heavy pressure vessels.
Flight Heritage
The technology has advanced from initial tech-demo status to flight-proven, flight-heritage hardware in LEO.
CubeSat and smallsat operators, companies building satellite constellations, and teams launching payloads via rideshare will benefit the most from water-based propulsion systems.
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.