World’s first space platforms utilising H2O2 in concentration above 98% – next level of green space propulsion

Polish leading R&D aerospace entity: Łukasiewicz – Institute of Aviation (Łukasiewicz – ILOT) concludes 2022 with major advances in its strategic area of green space propulsion and sets off with announcing ambitious plans for 2023 and further technology developments. With 25 projects from the European Space Agency (ESA) since Poland’s accession to ESA 10 years ago, Łukasiewicz – Institute of Aviation became a R&D hot spot in space propulsion in Central-Eastern Europe. Completed and ongoing projects with key spacecraft integrators (i.e. Airbus Defence & Space, OHB and Thales Alenia Space), as well as established players in space transportation systems (i.e. ArianeGroup, Avio, Nammo) and major new space companies – the institute have the ultimate goal of bringing new components, technologies and subsystems to the international market. The major added value provided to the space sector is the introduction of new hydrogen peroxide technology. Łukasiewicz – Institute of Aviation secured its patents, regarding obtaining new grades of High Test Peroxide (HTP), in 20 countries worldwide. While obtainable concentrations can exceed 99.99%, most ESA and national contracts concern the 98% concentration. Researchers at Lukasiewicz – Institute of Aviation claim that meeting the MIL-PRF-16005 standard is not enough and to ensure real long-term storability and high performance, the purity of HTP shall be beyond the one described in the propellant’s current standard and such an approach is indeed used at Łukasiewicz – ILOT.

ILR-33 AMBER 2K – updated version of the first in the world space vehicle to use 98% HTP grades

The institute’s suborbital in-flight experimentation platform – the ILR-33 AMBER rocket has been the workhorse for propulsion and space transportation technologies development, including HTP. While in 2017, thanks to its green hybrid main stage, it became the first in the world vehicle to use 98% HTP grades as oxidizer (unlike heritage satellite and space transportation systems worldwide). After its three successful low-altitude flights its new version, AMBER 2K, was launched in late 2022 and its payload was successfully recovered from the Baltic Sea.

The 2K version of AMBER shall ultimately allow for launching few-kilogram payloads to the Von Karman Line. The unique configuration of the rocket (parallel staging despite its small size) and use of a hybrid rocket motor ensures versatility and capability of carrying out a plethora of missions. The first external customer and payload provider is the Polish new space company Thorium Space.

Łukasiewicz – Institute of Aviation is also active in a wider range of in-flight demonstrations. Another “first” in the world was achieved by launching a small rocket using a rotating detonation engine utilizing liquid propellants in late 2021. Moreover, the institute is responsible for the green propulsion system of the FROG-H vertical take-off vertical landing (VTVL) demonstrator under development with i.e. CNES within the European Space Agency’s Future Launchers Preparatory Programme. The small hopper will use a monopropellant systems utilizing HTP.

Green engines

Work on bipropellant systems with 98% HTP as oxidizer and involves work on thrust levels up to circa 5-8 kN, with focus on European reignitable upper-stages and exploration with deep-throttleability as one of the major requirements. Valves for throttleable systems are of major interest due to both European and other international lunar missions and Poland becoming a signatory of the Artemis Accords in 2022.

Developed engine reignitability is achieved, apart from using catalyst beds, by utilization of proprietary fuels hypergolic with 98% HTP. In 2022 the national HIPERGOL project was successfully commenced and the first in the world 5 kN green hypergolic regeneratively-cooled engine using 98% HTP as oxidizer was demonstrated.

Testing of a 5 kN green hypergolic regeneratively-cooled rocket engine using 98% HTP as oxidizer. Credit: Łukasiewicz – Institute of Aviation

Additive technology implementing the 2021 ECSS-Q-ST-70-80C standard is widely utilized thanks to the institute’s laboratory capabilities.

“Recent investments allow for additive manufacturing of regeneratively cooled thrust chambers with use of copper alloy. Extensive in-house non-destructive testing capabilities along high-temperature material testing allow to build-up a wide research service package apart from space propulsion system hot-firings,” explains Ph.D. Eng. Adam Okniński, director of Space Technologies Center at Łukasiewicz – Institute of Aviation and member of the Space Propulsion Committee of the International Astronautical Federation.

Small satellite green propulsion

Moreover, build-up of know-how regarding HTP grades, storability and material compatibility allowed for the transition from work on propulsion components to full system development. While in 2023 Poland will celebrate the 50th anniversary of launching orbital space flight hardware (developed at the institute), the first green spacecraft propulsion system, fully developed in-house, is to be launched onboard the PIAST satellite constellation in the next years. The system using 98% HTP is to have aluminium alloy tanks to ensure demisability. Development of full propulsion systems, for satellites ranging from nanosatellites to those of up to 200 kg of mass, is accompanied by work on a green liquid apogee engine for large platforms.

Sea level testing of the GRACE Liquid Apogee Engine using green storable propellants – work conducted for the European Space Agency. Credit: Łukasiewicz – Institute of Aviation

Space debris mitigation

Work on sustainable technologies is not only limited to green propellants and demisable tanks. Łukasiewicz – Institute of Aviation has been involved in four consecutive contracts from the European Space Agency regarding use of solid rocket motors in autonomous robust deorbiting systems. In 2019 the institute pre-qualified for ESA the world’s possibly first solid propellant meeting ESA Clean Space requirements (i.e. no metal powder content, long-duration storability and proneness to space radiation) as well as system-level performance requirements of large satellite integrators (i.e. high performance while unprecedented low burn rate). In 2023 work is accelerating with ESA projects on the solid rocket motor and its thrust vector control system. An additional recent study was ordered for the Polish Space Agency, proving also the interest regarding potential national missions.

Rocket and satellite propulsion laboratory and testing capabilities

Parallel work in over a dozen ESA projects in 2023 requires focus on facility expansion, which has been ongoing. Łukasiewicz – Institute of Aviation received inter alia EU funding from the 2014-2020 Regional Operational Programme of the Mazowieckie Voivodeship for the creation of a modern Rocket and Satellite Propulsion Laboratory Center. The investment, exceeding a total of EUR 12 million, will allow testing green spacecraft thrusters and engines in vacuum with focus on HTP and green fuels as propellants.

The investment shall also include a major expansion of chemical propellant laboratories. Director General of Łukasiewicz – Institute of Aviation, Ph.D. Eng. Paweł Stężycki, chair of EREA (European Research Establishments in Aeronautics), describes the new green rocket and spacecraft propulsion facility: “By the end of 2023 we shall expand our offer regarding providing research services to the international space sector with the ultimate goal of increasing the share of commercial contracts”.

Today most of the revenues of the institute in the domain of aviation come from commercial international cooperation and the ongoing growth in the space domain is expected to also increase its share of industrial contracts. The 4 rocket propulsion hot-firing stands focused on green propulsion at the institute’s premises shall be therefore available by the end of this year. Taking into account other 2 existing external hot-firing facilities used at its domestic partners and another external facility under in-house design, the institute shall have a total of 7 hot-firing facilities available – this it on the European map of major test centers in spacecraft and rocket propulsion. 5 wind tunnels, environmental testing with the region’s largest thermal vacuum chamber and numerous material testing laboratories combined with implementation of ECSS standards, makes the Warsaw based institute attractive for a wider scope of spacetech developments, not limited to propulsion and space transportation.

Human resources for space

The implemented infrastructure and R&D projects allow for human resource development and enhancement of cooperation with technical universities and non-governmental organizations. The modern laboratory base is available for students doing scientific internships. Łukasiewicz – ILOT already supports several of the 10 student associations in Poland working on small experimental rockets and propulsion systems, seeking top talent and building up the Polish ecosystem and potential in space propulsion and space transportation systems. Constantly expanding its engineering team, Łukasiewicz – ILOT has as of the beginning of 2023 over 100 engineers dedicated to this technical domain and over 1500 in total, what allows in-house development of purpose-optimized facilities including not only modern laboratories, but also mobile infrastructure such as: rocket launch pads, propellant loading facilities, mission control etc. Source: Łukasiewicz – Institute of Aviation.

Łukasiewicz – Institute of Aviation is one of the most modern research institutions in Europe, with traditions dating back to 1926. Its main focus is delivery of new technologies. Research and development activities are focused on practical issues and anticipating key trends in aerospace propulsion systems, structures and related new technologies – mainly for space and unmanned vehicles.

As for space technologies, Łukasiewicz – Institute of Aviation main goal is to conduct R&D activities on space propulsion systems (including novel solid, liquid and hybrid rocket motors and engines), green propellants (including development, handling and testing environmentally friendly propellants) and space transportation systems. Work is continuing on the use of concentrated and purified hydrogen-peroxide for rocket propulsion and recent efforts allowed major advances in the fields of: robotics, defense systems, energetics, remote sensing, etc.