Space Propulsion Explained: Chemical, Electric and Emerging Approaches in 2026

Insider Brief

• The in-space propulsion market, the thrusters and tanks that satellites and spacecraft carry on board, is projected to grow from $1.2 billion in 2025 to $3.1 billion by 2030, a 22% compound annual growth rate, per Space Insider analysis.
• Three propulsion families dominate the sector: chemical, monopropellant and bipropellant, electric, Hall-effect thrusters and gridded ion engines, and cold-gas. The choice between them is one of the most consequential decisions in spacecraft design, trading thrust against efficiency.
• Electric propulsion’s share of the in-space market is projected to rise from around 42% in 2025 to 58% by 2030, driven by LEO mega-constellations and mass-efficient orbit raising. Chemical propulsion is growing in absolute terms but losing share.
• Green propellants, including LMP-103S, hydrogen peroxide (H₂O₂), HAN-based fuels and DLR’s HyNOx bipropellant, are reshaping chemical propulsion under EU REACH and NASA toxicity rules, replacing legacy hydrazine and hypergolic systems.

Every satellite that needs to change its orbit, keep station against drag and gravitational perturbations, or safely deorbit at end of life needs propulsion. The choice of propulsion system is one of the most consequential engineering decisions in spacecraft design: it determines how much of the spacecraft’s mass must go to fuel, how long missions can last, what maneuvers are possible, and how much the whole system costs to build and operate.

The sector is in the middle of a structural transition. Electric propulsion is scaling rapidly on the back of LEO mega-constellations and larger commercial platforms, while chemical propulsion is modernizing around a new generation of non-toxic “green” propellants. Meanwhile a wave of emerging approaches, nuclear thermal, water-based electric, advanced solar-electric, is moving from research into flight programs.

This article explains the main satellite propulsion types, compares how they work, covers the green and emerging approaches reshaping the sector, and sets out where the space propulsion market is heading.

What Is Space Propulsion and Why It Matters

Space propulsion is the generation of thrust to move a spacecraft. It breaks down into two distinct categories. Launch propulsion gets a vehicle from the ground to orbit and is dominated by large chemical rocket engines. In-space propulsion is everything that happens once the spacecraft has separated from its launch vehicle: orbit raising, station-keeping, attitude control, orbital transfers, deorbit maneuvers, and deep-space navigation. This article focuses on in-space propulsion, where the satellite propulsion types are most varied and the engineering trade-offs most interesting.

Two parameters define any propulsion system. Thrust is the force the engine produces, measured in newtons, and it determines how quickly a spacecraft can change velocity. Specific impulse (Isp) is the propulsion equivalent of fuel efficiency, measured in seconds, and it determines how much velocity change (delta-V) a given quantity of propellant can deliver. Chemical propulsion offers high thrust and lower Isp; electric propulsion offers very high Isp but very low thrust. The engineering choice depends on the mission.

For most missions, propulsion drives every downstream decision in spacecraft design: mass budget, mission duration, maneuver flexibility, and ultimately cost per kilogram of useful payload delivered to the right orbit. Understanding the propulsion options is essential to understanding how spacecraft actually work.

The Main Satellite Propulsion Types

Satellite propulsion breaks into three main families, with a fourth emerging category of hybrid and restartable systems.

1. Chemical propulsion releases stored chemical energy to produce high-thrust, short-duration maneuvers. It splits into two sub-types. Monopropellant systems use a single propellant, historically hydrazine, decomposed over a catalyst bed to produce hot gas. Isp typically sits at 150 to 230 seconds. Monopropellants are simple, reliable and well-suited to attitude control, small delta-V maneuvers and redundancy roles. Bipropellant systems combine a fuel with an oxidizer, traditionally monomethyl hydrazine (MMH) with nitrogen tetroxide (MON-3) as hypergolic propellants that ignite on contact. Isp of 290 to 320 seconds enables large delta-V maneuvers, direct orbital injection, and high-energy transfers. The trade-off is complex plumbing and toxic handling.
2. Electric propulsion (EP) accelerates propellant through electromagnetic forces rather than chemical combustion. Two architectures dominate: Hall-effect thrusters use a magnetic field to ionize and accelerate xenon, or increasingly krypton, propellant; gridded ion engines use electrostatic grids to accelerate ions. Both deliver specific impulse of 1,500 to 4,500 seconds, roughly ten times chemical propulsion, at the cost of very low thrust, typically millinewtons. This makes EP ideal for long-duration maneuvers such as orbit raising, station-keeping, and interplanetary transfers, but unsuitable where fast impulse is required.
3. Cold-gas propulsion uses pressurized inert gas, gaseous nitrogen (GN₂) is typical, released through nozzles. Isp is low, around 50 to 75 seconds, but the system is extraordinarily simple: no combustion, no toxicity, minimal plumbing. Cold-gas is widely used for small-satellite attitude control and as the reaction control system (RCS) on launch vehicle upper stages, including Falcon 9 and Falcon Heavy.
4. Hybrid and restartable systems are emerging as reusable launch vehicles and larger upper stages require greater maneuverability. SpaceX’s Starship, for example, is expected to introduce an autogenous methane/oxygen hot-gas RCS, an integrated bipropellant system that taps the main propellant tanks rather than carrying separate RCS storage.

Green and Emerging Space Propulsion Approaches

Regulatory pressure has fundamentally changed the chemical propulsion landscape. Tightening EU REACH rules and NASA toxicity mandates are pushing operators away from hydrazine and hypergolic propellants toward non-toxic “green” alternatives.

Green monopropellants are the most mature green category. LMP-103S, developed by Sweden’s ECAPS, is based on ammonium dinitramide (ADN) and has flown on multiple commercial and government missions. Hydrogen peroxide (H₂O₂) systems are scaling rapidly, with Nammo’s 220-newton thruster developed for Europe’s Vega C launcher, Agile Space Industries’ work on Blue Origin’s New Glenn, and PLD Space’s roughly 150-newton RCS on the Miura 5 kick stage. HAN-based (hydroxylammonium nitrate) monopropellants offer similar performance to LMP-103S and are under active development. The sector is also shifting from legacy 20 to 50 N thruster units to higher-thrust systems above 150 N, enabling faster attitude control and limited orbit-adjust capability without full bipropellant complexity.

Green bipropellants remain earlier-stage but are progressing. DLR’s HyNOx combines nitrous oxide with ethane; HTP/kerosene blends are in development in Europe; Aerojet Rocketdyne is working on HAN-based bipropellant systems in the United States. The target is hypergol-class performance without the handling overhead.

Beyond green chemical propellants, several emerging approaches are worth tracking. Water-based and iodine electric propulsion, from companies such as Pale Blue and ThrustMe, is reducing propellant cost and supply-chain complexity for small-satellite constellations. Nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) remain experimental, but DARPA’s DRACO program and NASA’s Fission Surface Power work indicate serious long-term interest for deep-space and lunar applications. Solar electric propulsion at scale is already flying on NASA’s Psyche mission and will power the Power and Propulsion Element of the Lunar Gateway.

Where the Space Propulsion Market Is Heading

Space Insider analysis valued the in-space propulsion hardware market, thrusters and tanks only, excluding propellant, at $1.2 billion in 2025, growing to $3.1 billion by 2030 at a 22% compound annual rate.

Electric propulsion is the primary growth engine. EP revenue is projected to rise from $0.5 billion to $1.8 billion between 2025 and 2030, a 30% CAGR, the fastest of any segment, driven by LEO mega-constellations, including new commercial platforms from Telesat Lightspeed and others, and by mass-efficient orbit-raising on larger GEO platforms. EP’s share of the in-space propulsion market is expected to rise from around 42% in 2025 to 58% by 2030.

Chemical propulsion is losing share but growing in absolute terms. Bipropellant systems are projected to grow from $0.5 billion to $1.0 billion, 16% CAGR, retaining an essential role in large delta-V maneuvers for GEO communications satellites, military ISR platforms, orbital transfer vehicles, and exploration missions such as Europa Clipper and JUICE. Monopropellant is growing at a slower 10% CAGR, $0.2 billion to $0.3 billion, sustained by its role in attitude control, backup propulsion and SmallSat redundancy. Human spaceflight, Orion, Lunar Gateway, commercial space stations, continues to rely heavily on chemical propulsion for its time-critical, high-thrust performance and extensive flight heritage.

The launch-vehicle side is a separate market with different dynamics. Space Insider analysis valued upper and kick-stage RCS hardware at $1.1 billion in 2025, growing to $1.6 billion by 2030 at an 8% CAGR. That total is dominated by SpaceX’s cold-gas systems, but the fastest value growth sits in high-thrust green monopropellant systems serving emerging commercial launchers such as Nammo’s Vega C thruster, and PLD Space’s Miura 5.

The underlying trend is consistent: electric propulsion is winning on share and growth, chemical propulsion remains indispensable for missions electric cannot serve, and green propellants are steadily displacing toxic heritage systems across the chemical side of the market.

Space Insider is the market intelligence platform for the space ecosystem, tracking 6,000+ companies, 4,500+ investors and mission statistics through 2042. This article draws on our broader space propulsion market intelligence, including our In-Space Propulsion 2025–2030 Market report and Upper & Kick Stage RCS Thrusters and Tanks Market report. Contact us to discuss a specific space propulsion question.

Frequently Asked Questions

What is space propulsion?

Space propulsion is the generation of thrust to move a spacecraft. It splits into two categories: launch propulsion (getting from the ground to orbit, dominated by large chemical rocket engines) and in-space propulsion (everything after launch separation, including orbit raising, station-keeping, attitude control, orbital transfers, deorbit maneuvers and deep-space navigation). In-space propulsion is where engineering trade-offs are most varied, with chemical, electric and cold-gas families each suited to different missions.

What are the main types of satellite propulsion?

Four families cover most satellite propulsion. Chemical propulsion (monopropellant systems at 150–230 seconds Isp for attitude control and small delta-V, and bipropellant systems at 290–320 seconds Isp for large delta-V maneuvers) offers high thrust. Electric propulsion (Hall-effect thrusters and gridded ion engines at 1,500–4,500 seconds Isp) offers ten times the efficiency of chemical but very low thrust. Cold-gas systems (50–75 seconds Isp) are simple and non-toxic, used for SmallSat attitude control and launch-vehicle RCS. Hybrid and restartable systems are emerging on reusable launchers.

What is the difference between chemical and electric propulsion?

Chemical propulsion releases stored chemical energy to produce high thrust over short durations, with specific impulse of 150–320 seconds. Electric propulsion accelerates propellant through electromagnetic forces, delivering specific impulse of 1,500–4,500 seconds – roughly ten times the efficiency – but at very low thrust (typically millinewtons). The trade-off is mission-driven: chemical wins where fast impulse is needed (orbital injection, time-critical maneuvers), electric wins on long-duration maneuvers like orbit raising, station-keeping and interplanetary transfers.

What are green propellants in space propulsion?

Green propellants are non-toxic alternatives to legacy hydrazine and hypergolic propellants, developed in response to tightening EU REACH rules and NASA toxicity mandates. Mature green monopropellants include LMP-103S (ECAPS, ADN-based), hydrogen peroxide systems (Nammo, Agile Space, PLD Space) and HAN-based fuels. Green bipropellants are earlier-stage but progressing, including DLR’s HyNOx (nitrous oxide + ethane), HTP/kerosene blends and HAN-based bipropellant work at Aerojet Rocketdyne.

How big is the space propulsion market?

Space Insider analysis values the in-space propulsion hardware market (thrusters and tanks, excluding propellant) at $1.2 billion in 2025, growing to $3.1 billion by 2030 at a 22% CAGR. Electric propulsion is the fastest-growing segment at 30% CAGR ($0.5B to $1.8B), bipropellant chemical grows at 16% CAGR ($0.5B to $1.0B), and monopropellant chemical at 10% CAGR ($0.2B to $0.3B). The separate upper- and kick-stage RCS market is valued at $1.1 billion in 2025, growing to $1.6 billion by 2030 at 8% CAGR.

Why is electric propulsion gaining market share over chemical?

Electric propulsion is winning share because its very high specific impulse (1,500–4,500 seconds) delivers more delta-V per kilogram of propellant – a critical advantage for LEO mega-constellations launching hundreds of satellites at a time, and for mass-efficient orbit-raising on larger GEO platforms. EP’s share of the in-space propulsion market is projected to rise from around 42% in 2025 to 58% by 2030. Chemical propulsion remains essential for missions requiring fast impulse, large single-burn delta-V, and human spaceflight where flight heritage and high thrust are non-negotiable.