Electric Propulsion Companies

Momentus

San Jose, United States commercial

Momentus was a commercial in-space transportation company that developed the Vigoride orbital service vehicle for satellite deployment and hosted payload services using water plasma propulsion. The company went public via SPAC in 2021 but faced severe regulatory and financial difficulties. In 2021, the SEC charged the company and its co-founder with making false and misleading statements about the technology's performance. The company remained listed on Nasdaq (MNTS) and carried out a 1-for-17.85 reverse stock split in December 2025 to regain compliance with the exchange's minimum bid price. Vigoride flew several missions to ISS but the broader orbital transfer vehicle business struggled to reach commercial viability. As of 2025-2026 the company has dramatically scaled back operations.

Astra

Alameda, United States commercial

Astra Space is an American launch and spacecraft-propulsion company that developed small orbital rockets with a goal of frequent, low-cost launches for small satellites. Founded in 2016 in Alameda, California, and led by CEO Chris Kemp and CTO Adam London, Astra went public via SPAC in 2021 at a $2.1B valuation. The company's Rocket 3.3 achieved orbit in November 2021 but suffered multiple launch failures. Astra's Rocket 4 development was abandoned in 2022 after two LV008 failures. In July 2023, Astra announced it was suspending launch vehicle development indefinitely and laid off most of its staff, effectively shutting down the launch business. Co-founders Chris Kemp and Adam London took the company private at $0.50 a share in July 2024. It now builds satellite electric-propulsion systems (from the 2021 Apollo Fusion acquisition), reported 2025 revenue of about $45 million at breakeven EBITDA, shipped its 110th engine system in January 2026, and is developing Rocket 4 under a Defense Innovation Unit contract worth up to $44 million, with a first flight targeted for 2026.

Ad Astra Rocket

Webster, United States commercial

Ad Astra Rocket Company, founded in 2005 and based in Webster, United States, is a spaceflight technology company specializing in advanced plasma propulsion. The company’s core product is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR®) engine, a novel system designed to revolutionize in-space transportation. Unlike traditional chemical rockets, VASIMR® utilizes plasma physics to achieve significantly higher performance – reportedly ten times that of chemical rockets – while using a fraction of the fuel. Ad Astra’s key technological focus is harnessing high-power plasma physics for efficient and versatile propulsion. Current development includes prototypes like the VX-200SS™ which have undergone testing at the 100kW level within the company’s vacuum chamber, bringing the technology to a Technology Readiness Level (TRL) of 5 through a partnership with NASA’s NextSTEP program. The company envisions a broad range of applications for VASIMR®, including cargo transfer in cislunar space, space station reboost services, asteroid mining/deflection, space debris removal, and enabling faster, more efficient missions to Mars and beyond. While not currently detailing specific commercial deployments, Ad Astra is positioning VASIMR® as a critical component for building a sustainable space economy by lowering the cost and increasing the feasibility of in-space transportation. Additionally, through its Costa Rican subsidiary, the company is exploring integrated clean energy solutions based on green hydrogen storage.

Lúnasa Space is a United Kingdom-based company developing in-space transportation infrastructure, specifically focused on last-mile satellite delivery in Low Earth Orbit (LEO). Their core offering is the VIA reusable orbital transfer vehicle (OTV), designed to precisely deliver satellites to their desired orbital slots and provide on-orbit services. This addresses a critical need in the rapidly expanding LEO satellite constellation market, where traditional launch methods often lack the precision and flexibility required for optimal deployment. The VIA OTV differentiates itself through a focus on fuel preservation and life-extension services for existing satellites. This capability suggests a proprietary propulsion system and orbital maneuvering technology enabling efficient and prolonged on-orbit operations. By offering these services, Lúnasa aims to extend the operational lifespan of valuable satellite assets and reduce the costs associated with replacement. Recent news indicates Lúnasa Space was awarded funding through the UK Space Agency’s Space Clusters Enhancement Programme (SECP) to accelerate development of their “Cosmic Labs” orbital platform. This suggests a broader ambition beyond simple transport, potentially encompassing in-space servicing, manufacturing, or research capabilities. Positioned within the growing in-space servicing, refueling, and life extension (ISSRL) market, Lúnasa Space offers a specialized solution for precise satellite deployment and on-orbit maintenance. Their reusable OTV and focus on fuel efficiency represent a key value proposition for satellite operators seeking to maximize the return on investment for their space assets.

Orbion Space Technology

Houghton, Michigan, United States commercial

Orbion Space Technology is an electric propulsion manufacturer headquartered in Houghton, Michigan, founded in 2016 as a spinout from Michigan Technological University by Dr. Brad King and Lyon Brad King. The company designs and produces Hall-effect thrusters — the Aurora HET — for small satellites in the 100–1,000 kg class, where efficient low-thrust electric propulsion is increasingly required for orbit maintenance, collision avoidance, and orbit raising. Orbion's Aurora thruster is designed for high production rates and has been selected by multiple commercial smallsat customers, including constellation operators and government programs. The company has announced manufacturing scale-up to hundreds of units per year and has raised Series B and C rounds from investors including Material Impact, Invest Michigan, and Wake Capital. Orbion competes in a growing electric-propulsion market alongside Busek, ENPULSION, ThrustMe, Phase Four, Morpheus Space, and Exotrail, each targeting different thrust ranges and power classes. Orbion's focus on North American supply-chain independence has attracted particular interest from U.S. national-security customers.

Rafael Space Propulsion, a division of the larger Rafael Advanced Defense Systems founded in 1948 and headquartered in Haifa, Israel, develops space propulsion systems as part of its broader portfolio of defense technologies. While specific details regarding its space propulsion offerings are limited in the provided information, Rafael is demonstrably a technology-focused company with expertise in areas crucial to space systems, including missile systems, advanced communications, and laser technology – as evidenced by the development of systems like the IRON BEAM high-energy laser weapon system. The company’s core competencies extend beyond propulsion to encompass a wide range of defense solutions, including air and missile defense systems (IRON DOME, TROPHY APS), land warfare technologies, and naval systems. This suggests a potential for synergistic development and application of technologies across both terrestrial and space-based platforms. Rafael maintains a significant global footprint, serving customers in over 20 NATO countries and operating through a network of subsidiaries, joint ventures, and partnerships in locations including Israel, the USA, Brazil, and Europe. Recent news highlights Rafael’s focus on expanding production of existing systems like Iron Dome and delivering new capabilities such as the IRON BEAM laser system, as well as advancements in tactical communications and loitering munitions. This indicates a commitment to both established defense programs and the development of next-generation technologies. The company actively pursues industrial cooperation programs, emphasizing technology transfer and localized manufacturing to foster strong, long-term customer relationships.

SITAEL

Bari, Italy commercial

SITAEL is a Bari, Italy-based space technology company founded in 2014 (a spin-out from the Alta aerospace group), developing small satellite platforms, electric propulsion systems, and complete small satellite missions. SITAEL has established itself as one of Italy's leading small satellite prime contractors and as a significant manufacturer of Hall-effect thrusters for the European market — a dual capability in spacecraft systems and propulsion that distinguishes it from pure component suppliers or mission operators. SITAEL's satellite platform family covers the microsatellite range: the S-50 (50 kg class), S-150 (150 kg), and MMTS (Multi-Mission Technology Satellite) platforms provide standardized bus architectures for Earth observation, technology demonstration, and scientific payloads. These buses are designed with modular interfaces for payload accommodation, supporting optical, SAR, and communications instruments from Italian and international customers. SITAEL serves ESA Earth observation programs and Italian national programs through the Italian Space Agency (ASI), delivering complete turnkey missions from design through launch and operations. In electric propulsion, SITAEL manufactures the HT-series Hall-effect thrusters (HT-100, HT-400, HT-1000) across a power range from approximately 100W to 1kW, covering the propulsion requirements from 3U/6U CubeSats through microsatellites in the 50–200 kg class. Hall thrusters provide xenon plasma propulsion with specific impulse of 1,200–2,000 seconds — dramatically higher than chemical propulsion — enabling significant delta-V for orbit raising, inclination changes, and end-of-life deorbit with a fraction of the propellant mass required by chemical systems. SITAEL's FEEP (Field Emission Electric Propulsion) thrusters serve even smaller platforms, complementing its Hall thruster lineup. SITAEL's Bari location in southern Italy — historically underrepresented in the Italian space industry concentrated in Rome and Turin — benefits from ASI support for southern Italian industrial development. The company competes with AAC Clyde Space, Airbus OneWeb Satellites, and OHB for European small satellite prime contracts, and with Safran Spacecraft Propulsion, Enpulsion, and Exotrail for European electric thruster supply.

T4i

Padova, Italy commercial

T4i, founded in 2014 and based in Padova, Italy, is a space technology company specializing in the development of propulsion systems for small satellites and launch vehicles. The company focuses on both chemical and electric propulsion, offering solutions for in-space mobility and access-to-space applications. T4i’s product portfolio includes cold gas systems (IANUS & PERSEUS) utilizing Freon propellant, monopropellant systems leveraging Hydrogen Peroxide (ALPHARD family), and electric propulsion systems (REGULUS family) employing iodine as propellant. A key differentiator for T4i is its commitment to “green propulsion” technologies, indicated by its focus on alternative propellants and efficient system designs. The company’s systems are designed for a range of applications including collision avoidance, inspection, proximity operations, deployment, and orbital maneuvers, particularly for nano- and micro-satellites, as well as orbital transfer vehicles. While specific mission details or customer lists are not publicly available, T4i actively participates in industry events such as Space Tech Expo Europe and Aerospace & Defense Meetings, demonstrating its engagement with the broader space industry. The company is also investing in research and development of technologies like RF plasma propulsion and plasma antennas, suggesting a forward-looking approach to innovation in the space sector.

ThrustMe

Verrières-le-Buisson, France commercial

ThrustMe is a French electric propulsion company developing iodine-propellant propulsion systems for small satellites. Founded in 2017 as a spin-off from Ecole Polytechnique and headquartered near Paris, the company's signature product is the NPT30-I2 — the world's first iodine-propellant Hall effect thruster to fly in space, demonstrated on a Swarm Technologies satellite in 2021. Iodine offers significant advantages over conventional xenon propellant: it stores as a solid at room temperature (no high-pressure xenon tanks needed), is non-toxic, far cheaper, and has similar performance to xenon when ionized. This makes ThrustMe's thrusters particularly attractive for CubeSats and ESPA-class satellites where mass and volume are at a premium. ThrustMe has supplied thrusters to commercial constellation operators, ESA missions, and university satellite programs, and received ESA BIC funding.