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Hybrid Propulsion Module for transfer to GEO orbit

Periodic Reporting for period 2 - HYPROGEO (Hybrid Propulsion Module for transfer to GEO orbit)

Reporting period: 2016-02-01 to 2018-01-31

Independent access to space is a key component of the European Space Policy. The competition is increasing in this area both for the full launching systems and the key subsystems. Cost-effectiveness becomes the main driving factor.

HYPROGEO’s ambition is to develop the key technologies enabling a propulsion module based on hybrid chemical propulsion.
This application is very challenging as it has to overcome the limitations of classical hybrid engines (long duration burns, constant thrust below 1kN, specific impulse comparable to bi-liquid propulsion) while answering the issues linked to current bi-liquid engines (toxicity, architecture complexity and cost) and electric propulsion (cost and transfer duration).

The main challenges concern the feasibility of managing near-anhydrous hydrogen peroxide (HTP), sustaining long duration burns with constant thrust, and integrate the hybrid propulsion within operational spacecraft and confirm the economic and technical effectiveness.

Therefore, the main technical objectives of HYPROGEO are centered on four building blocks:
• Combustion chamber: to develop and test innovative isochoric architecture.
• High endurance nozzle: to develop a lightweight nozzle capable of withstanding the thermal load and specific erosion caused by the long term exposure of the reaction products.
• HTP: produce at industrial scale up to 98% concentration HTP, aiming theoretical ISP equal to state-of-the-art NTO/MMH apogee engines.
• Catalytic injector: the challenge is to ensure compatibility to the HTP and be able of rapid ignition.

These four elements influence the performance of the system; scientific achievements in these technological domains and TRL level increase up to 4-5 are required in order to propose the development of an operational system.
The main objectives achieved in the first period (M1 – M12) were to:
• define the main requirements of the propulsive system, main hybrid engine & associated hardware in term of targeted thrust level, firing durations, accommodation constrains, number of re-ignition/cycles, …
• consolidate the overall test strategy implemented throughout the project
• perform the first characterization tests on key component technologies
• make a trade-off between several innovative hybrid engine combustion chamber configurations
• define and implement a communication strategy

For the second period (M13-M24), the work performed focused on the following main objectives:
• WP1: Feed market analysis & technological roadmap + verification plan update
• WP2: Combustion chamber concept validation and regression rate characterization through the test of a small scale breadboard
• WP3: Nozzle design & manufacturing process optimization. Erosion evaluation during an hybrid engine firing
• WP4: Validation of the operational compatibility of the use and decomposition of HTP concentrated at 98% & catalytic injector design and test
• WP5: HTP storage stability & production optimization
• WP6: Update communication & dissemination support through the website and a video
• WP7: Technical meetings organization & EU interface

For the third and last period (M25-M36), the work performed focused on the following main objectives:
• WP1: Feed market analysis & technological roadmap + verification plan update
• WP2: Design, manufacturing and test of the demonstrator combustion chamber and integration of the complete demonstrator
• WP3: Design, manufacturing and test of the low-erosion nozzle
• WP4: Design, manufacturing and test of the catalytic injector on the demonstrator engine and Design, manufacturing and test of the monopropellant HTP auxiliary thruster
• WP5: 98% HTP production for the supply chain evaluation and basic engineering of the full scale production plant
• WP6: Update communication & dissemination support
• WP7: Technical meetings organization & EU interface
As an overall conclusion of the HYPROGEO project, we can validate the completion of the project objectives, which were first to study a new cost-effective subsystem for access to space using hybrid chemical propulsion technology and confirm the benefits as a complementary and cost-effective alternative to classical bi-liquid chemical engines and all-electric propulsion. The second objective focused on providing significant scientific progress and increase the European excellence and know-how in critical technologies and components of an operational hybrid propulsion system, in all 4 technical challenges
1st Challenge: Achieve high specific impulse
− Fuel selection compatible with space applications and providing the highest theoretical ISP
− Combustion efficiency with low regression rate
− Optimization of catalyzer and increase of HTP concentration
2nd Challenge: Sustain long duration burn with medium thrust
− Duration of burns
− Thrust stability
− Thermal protection (nozzle and combustion chamber)
− Geometrical arrangement of the fuel for long duration burns and constant performance with time
− Compatibility with oxidizers.
3rd Challenge : Demonstrate the feasibility of using High concentration HTP
− High concentration issues (production, storage, decomposition, safety of operations)
− Compatibility with material and subsystems (lifetime of tanks)
4th Challenge: Integrate the hybrid propulsion within operational spacecrafts and confirm the economical and Technical effectiveness
− Confirmation of cost impact and reduction of design complexity
− Accommodation of the hybrid propulsion modules within the spacecraft
− Geometrical arrangement of tanks
− Reaction control thrusters
− Trade-off between upper stage and apogee engine scenarios.

Analysis of the assets of hybrid propulsion in HYPROGEO’s target of long duration and stable firings leaded to the definition of a preferred application as an independent kick-stage module compatible with full or partial geostationary transfer of geostationary satellites.
One of the interesting impacts identified by the WP1 activities was the identification of the best compromise in terms of performance management at satellite level between the kick-stage chemical propulsion (to quickly raise the orbit since its injection from launcher), and the electric propulsion on-board the spacecraft. This optimization search aims to increase the satellite operational lifetime (with the maximization of Xenon mass where in geostationary orbit) without leading to over-constraining durations currently encountered with full electric propulsion transfers.

Positive impacts have been demonstrated in all technical domains as first exploitable results are currently being disseminated, from an innovative isochoric combustion chamber concept for long duration and constant thrust, a high-temperature and low-erosion material development for a high endurance nozzle, a very performing test of a long duration catalytic bed using 98% HTP (European first), and development of a HTP production plant of up to a top-level concentration over 98%.

Lastly, the competitive positioning (SWOT) of hybrid engines was analyzed from the technical perspective. Hybrid engines are simpler, safer, and cheaper than chemical or electric ones. In terms of ISP and thrust, they provide an interesting in-between alternative to chemical and electric engines.
Hybrid demonstrator hotfiring test
WP Progress page 1
WP Progress page 2