Rocket Engines Companies

Yuzhnoye Design Bureau (also transliterated Pivdenne, formally the State Enterprise "Yuzhnoye Design Bureau named after M.K. Yangel") is Ukraine's principal rocket and spacecraft design organization, headquartered in Dnipro and founded in 1951 by Soviet missile designer Mikhail Yangel. During the Soviet era it designed a series of intercontinental ballistic missiles, including the R-12, R-14 and R-16, under the OKB-586 designation; it continues ballistic-missile design work today, including the Hrim-2, alongside civilian and commercial space programs. Its launch-vehicle heritage includes the Zenit family, the Dnepr launcher (a converted R-36 ICBM used for commercial satellite launches), and the Cyclone family. Cyclone-4M remains in development without a launch site: Maritime Launch Services ended its Nova Scotia agreement in 2024 and has since signed with another launch provider. Yuzhnoye designed the first-stage core of Northrop Grumman's Antares rocket, flown on Cygnus cargo missions to the International Space Station, under a partnership with the former Orbital Sciences Corporation; Northrop moved that work to Firefly Aerospace in 2022 and the last Yuzhnoye-built stage flew in August 2023. The bureau also designs satellites, including the Sich Earth-observation series (Sich-2-1, Sich-2-M, Sich-3-O, Sich-3-P), the Mikrosat and Ionosat-Micro small satellites, and YuzhSat variants, along with a range of rocket engines and steering thrusters, including the RD-843 and RD-861K. Yuzhnoye is a fully state-owned enterprise reporting to Ukraine's State Space Agency and is in the process of being converted into a joint-stock company wholly owned by the state. It works closely with, but is organizationally distinct from, the Pivdenmash manufacturing plant that builds the hardware it designs. As of 2026 the bureau remains active despite the disruption the Russian invasion has caused to Ukraine's space-manufacturing base.

Interorbital Systems is a privately held American rocket company founded in 1996 by Roderick (Rod) and Randa Milliron and based at the Mojave Air and Space Port in Mojave, California. The company has spent almost three decades developing the modular NEPTUNE family of orbital launch vehicles, built around a Common Propulsion Module (CPM) — a cluster of small liquid-oxygen/densified-propane rocket engines, each producing roughly 4,500 lbf of thrust — that can be grouped in different quantities to scale the rocket's payload capacity; related TRITON and TRITON HEAVY variants have also been proposed. Alongside the launch vehicle work, Interorbital sells low-cost 'TubeSat' and 'CubeSat' personal satellite kits to schools, hobbyists and research groups, intended to be flown as rideshare payloads once NEPTUNE or a partner vehicle is available; the company has used ISRO and JAXA rideshare opportunities to fly some customer payloads, and also developed the suborbital NEUTRINO and TACHYON sounding rockets. Interorbital served as the launch-vehicle partner for Team Synergy Moon in the Google Lunar X Prize, and earlier competed for the Ansari X Prize and America's Space Prize. Despite multiple announced static-fire and suborbital test campaigns dating back to the 2000s, Interorbital Systems has not yet completed an orbital launch; as of October 2023 NEPTUNE, TRITON and TRITON HEAVY remained in development, with the company reporting around a dozen employees as of 2017. The company continues to operate from Mojave.

Evolution Space

Mojave, United States commercial

Evolution Space (Evolution Space and Energetics Corp) is a solid rocket motor company headquartered in Mojave, California, with an additional propulsion production facility at NASA's Stennis Space Center in Mississippi, positioning itself as a 'solids as a service' partner for U.S. defense and aerospace customers. Its Whiplash and Maelstrom product lines are tailorable fast-burn and extended-boost solid propulsion systems tested at hypersonic speeds above Mach 5 and altitudes exceeding 100 km. In August 2024 the company won an Air Force SBIR Phase II contract for hypersonic boost and target propulsion solutions, and in September 2024 it carried out sea-based rocket testing in partnership with The Spaceport Company.

IHI Aerospace

Tokyo, Japan commercial

IHI Aerospace Co., Ltd. is Japan's primary solid rocket motor manufacturer and a critical component of JAXA's launch vehicle propulsion supply chain, established in 1960 as the aerospace division of Ishikawajima Harima Heavy Industries (IHI Corporation) and formally spun off as a dedicated subsidiary in 2003. The company supplies the solid propulsion systems for both of JAXA's primary orbital rocket families and has been central to Japanese rocketry since the early days of ISAS's pencil-rocket sounding vehicle programs. For the Epsilon solid orbital rocket — JAXA's science satellite launcher currently flying in its Epsilon-S upgraded configuration — IHI Aerospace manufactures the complete solid motor stack: the M-35 first stage motor (the largest element, providing the majority of the vehicle's total impulse), the M-34c second stage motor, and the KM-V2b third stage motor, representing virtually the entire propulsive system of a vehicle designed for autonomous launch operations with minimal ground control staffing. IHI's motor quality and reliability underpins JAXA's ambitious goal of a nearly automated launch process. For the H-series liquid rocket family — H-IIA, H-IIB (now retired), and the new H3 — IHI Aerospace manufactures the Solid Rocket Boosters (SRBs) that provide critical additional thrust at liftoff: the SRB-A and SRB-3 variants strap onto the H-IIA and H3 core stages respectively, enabling the heavy-payload configuration needed for GTO launches of commercial and government telecommunications satellites. Two or four SRBs can be attached to H-IIA to tune the payload capacity. IHI Aerospace also contributes to liquid propulsion: IHI Group's aerospace division participates in the turbopump manufacturing for JAXA's LE-7A engine (H-IIA/B) and the new LE-9 engine (H3), bridging solid and liquid propulsion expertise. Historical heritage includes contributions to ISAS's M-series solid rocket motors culminating in the M-V (Mu Five), Japan's largest solid rocket capable of 1.8 tonnes to LEO, which flew from 1997-2006 carrying landmark science missions including Hayabusa asteroid sample return. Domestically IHI competes and collaborates with Nissan's historical aerospace division and Daicel Corporation for propellant chemistry.

Łukasiewicz – Institute of Aviation

Warsaw, Poland research institute

Łukasiewicz – Institute of Aviation is a Polish state aerospace research institute headquartered in Warsaw, tracing its roots to 1926 and reorganized in 2019 as part of the government's Łukasiewicz Research Network. Its rocketry program produced the multistage ILR-33 AMBER suborbital rocket, pairing twin solid boosters with a hybrid main engine; three early AMBER flights between 2017 and 2019 reached altitudes up to 23 km. On 3 July 2024, the upgraded ILR-33 AMBER 2K — the first rocket in the world to use 98% hydrogen peroxide as an oxidizer — launched from Norway's Andøya Space Center and reached 101 km, becoming the first Polish-built rocket to reach space. Beyond rocketry, the institute continues to offer propulsion testing, design, and manufacturing services to industry.

Nammo

Raufoss, Norway commercial

Nammo is an international aerospace and defense company with over 3,700 employees across 27 production sites in 11 countries. The company provides rocket and missile propulsion for European and North American programs since 1948, including motors for AMRAAM, ESSM, and IRIS-T missiles. Nammo developed Norway's first indigenous sounding rocket and has an ESA contract for the Heracles lunar lander engine.

Pratt & Whitney Space Propulsion

West Palm Beach, United States commercial

Pratt & Whitney Space Propulsion (now operating as Aerojet Rocketdyne following its 2013 acquisition by GenCorp, and subsequently as L3Harris's Aerojet Rocketdyne following the 2023 acquisition) is the West Palm Beach, Florida heritage site for Pratt & Whitney's rocket engine development, most famous for producing the RL10 — the world's most flight-proven upper stage engine with over 500 successful space missions. The RL10 uses liquid hydrogen and liquid oxygen in an expander cycle (where fuel is heated by the engine chamber to drive the turbopump, with no separate preburner), achieving specific impulse of 450-465 seconds — the highest Isp of any production liquid rocket engine — making it the gold standard for upper stages where maximum efficiency per kilogram of propellant is paramount. RL10 variants (A-4, B-2, C-1, C-3) power the Centaur upper stage of Atlas V and Vulcan, Boeing's DCSS (Delta Cryogenic Second Stage), and have been selected for ULA's new Vulcan Centaur as RL10Cs. The RS-25 (Space Shuttle Main Engine, SSME) — the world's most sophisticated liquid rocket engine — was developed at what is now Aerojet Rocketdyne's Canoga Park facility, now refurbished for NASA's Space Launch System (SLS): each SLS launches with four RS-25s producing 490,000 lbs thrust each at near-maximum efficiency. Pratt & Whitney also developed the RL50, COBRA, and various advanced concepts for upper stage applications. The company's space propulsion heritage, concentrated in the RL10 engine which has accumulated thousands of starts and hundreds of upper stage missions without a single in-flight failure attributable to the engine, represents one of the most reliable engineering achievements in launch vehicle history.

Ursa Major

Berthoud, Colorado, United States commercial

Ursa Major is a privately held liquid rocket engine manufacturer based in Berthoud, Colorado, founded in 2015 by Joe Laurienti, a former SpaceX and Blue Origin propulsion engineer. The company specializes in turbopump-fed liquid oxygen/kerosene engines designed for commercial launch vehicles and hypersonic vehicle applications, positioning itself as a dedicated U.S.-based propulsion supplier that lets launch integrators avoid vertical integration. Its flagship products are the Hadley engine (a 5,000 lbf-class staged-combustion engine used by operators including Stratolaunch) and Ripley (a 50,000 lbf-class engine intended for medium-lift rockets). The company has also publicly disclosed Draper, a solid-liquid hybrid engine concept aimed at the hypersonic systems market. In 2024 Ursa Major announced "Lynx," a modular solid rocket motor production capability intended to shore up U.S. solid-motor supply for defense customers. Funding rounds through 2023–2024 from investors including Explorer1 Fund, BlackRock, Eclipse Ventures, and Space Capital have pushed valuations into the hundreds of millions. Government customers include the U.S. Air Force, U.S. Navy, and DARPA under hypersonic propulsion contracts. Ursa Major's strategy is to serve both the commercial smallsat-launch market and the U.S. defense propulsion base as a merchant-engine supplier.

X-Bow Systems

Albuquerque, United States scaleup

X-Bow Systems is a solid rocket motor manufacturer headquartered in Albuquerque, New Mexico, founded in 2016 to apply additive manufacturing to solid propulsion production, cutting motor lead times and enabling its 'Rocket Factory in a Box' concept. The company raised $70 million in July 2024 to expand solid rocket motor production capacity, and holds U.S. defense contracts including a $17.8 million 2023 Air Force Research Laboratory award to demonstrate additive-manufactured solid rocket motors and a 2024 contract to develop motors for U.S. Navy Standard missiles. X-Bow also builds small launch vehicles, having flown its Bolt sounding rocket in July 2022, and operates facilities across multiple U.S. states.