Individual Research Projects (IRPs)

• Host institution:
  Technische Universität Dresden
• Main Supervisor:
  Dr. Tino Schmiel
  
• Enrolment:
  Technische Universität Dresden

Problem Definition: In reusable systems, health monitoring of critical subsystems is mandatory during operation in order to account for all influences and to ensure a safe and reliable access to space independent from the previous uses.

Research Objectives:

1. Investigation of different possible sensor technologies and requirements of the various RLV subsystems.
2. Development of models, strategies, algorithms for exploitation of sensor measurement results for the critical evaluation of all RLV mission phases.
3. Investigation of their respective structural, electrical and communication integration into the RLV subsystems like engines or structures.

Expected Results:

1. Selection of sensors for time dependent data such as temperature and pressure distribution, critical gases, vibration, shock, electrostatic, -magnetic loads, acoustic emission, thermal insulation degradation etc. for integration in Wireless Sensor Networks (WSNs).
2. Strategies for the integration of WSNs in RLV subsystems including signal propagation power supply, structural integration and linking strategy.
3. Algorithms for health monitoring of RLV, matching their mission design.
4. A preliminary follow-up actions plan for maintenance and re-usage based on results of diagnosis and prognosis.

• Host institution:
  Technische Universität Dresden
• Main Supervisor:
  Dr. Christian Bach
  
• Enrolment:
  Technische Universität Dresden

Problem Definition: The efficiency of reuse depends directly on the concept for RLV recovery, including the extend of recovery (e.g. engine section vs. full stage) and the recovery strategy (propelled, by parachute, mid-air retrieval, glide-back, etc.). Especially for retro propulsion as utilised in vertical landings, the interaction of nozzle and ambient flow needs to be investigated.

Research Objectives:

1. Detailed analysis of different recovery strategies and their influence on structural and propulsion system design based on the system design inputs of ESR3.
2. Investigation of vertical landing scenarios including flow conditions derived from trajectory analysis conducted by ESR14.
3. Numerical and experimental examination of retro engine operation.
4. Identification of favourable engine layouts and system design effects including the particular analysis of advanced nozzle concepts in collaboration with ESR6.

Expected Results:

1. Ability to assess the influence of RLV recovery strategies on system and mission design with particular focus on propellant consumption for different vertical landing concepts.
2. A numerical and experimental database for retro engines with reverse-flow interactions.
3. Justified choice of a favourable engine layout in collaboration with ESR4.

• Host institution:
  German Aerospace Center
• Main Supervisor:
  Dr. Martin Sippel
• Enrolment:
  Universität Bremen

Problem Definition: Due to the complexity of RLVs, one ESR will cover system design aspects. A fast interdisciplinary design process is key to successful analyses of future RLV. Fast structural design methods are needed which take into account the actual flight loads, allow for rapid variation in the design space and are flexible enough for complex cross-section shapes.

Research Objectives:

1. Definition of (semi-) reusable launcher concepts.
2. Architecture trade-offs and identification of a favourable reusable launcher concept.
3. Integrated structural pre-design with aerothermal interactions in collaboration with ESR7

Expected Results:

1. Definition of (semi-) reusable launcher concepts based on systematic architecture trade-offs. These concepts are also to be studied on specific aspects in WP2–WP4.
2. Integrated structural design of RLV considering aerothermal effects investigated by ESR7 taking into account lightweight but robust solution and estimation of performance impact.
3. RLV design guidelines and engineering methods for fast-integrated multi-disciplinary analyses.

• Host institution:
  German Aerospace Center
• Main Supervisor:
  Prof. Michael Oschwald
  
• Enrolment: Rheinisch-Westfälische Technische Hochschule Aachen

Problem Definition: Future rocket engines aimed at RLV applications require high fatigue life and optimised engine cycles w.r.t. maximum durability and minimum maintenance costs. This requires novel approaches in engine design and verification.

Research Objectives:

1. Implementation of SOTA models for fatigue life of rocket engine components in rocket engine cycle analysis tools.
2. Validation of methods with published data for engine durability.
3. Conduction of parametric studies on different liquid-fuelled rocket engine cycles for different propellant combinations.
4. Investigation of the achievable fatigue life w.r.t. different operating conditions (thrust, pressure and propellant mixture ratio as functions of time).
5. Identification of favourable rocket engine cycle layouts in terms of maximum fatigue life w.r.t. performance requirements (specific impulse, TWR) derived from RLV mission profiles provided by ESR3.

Expected Results:

1. Ability to assess durability of new and existing liquid rocket engine concepts.
2. Justified choice of an engine cycle, propellant combination and operating conditions for a liquid rocket engine optimized for reusability.

• Host institution:
  Sitael
• Main Supervisor:
  Dr. Giovanni Pace
  
• Enrolment:
  Università di Pisa

Problem Definition: The recent inclusion of hydrazine into the candidate list of SVHC in accordance with the REACH regulation has made the identification and the experimental investigation of green propellants critical for future launchers. Particularly in current upper stages, the primary propulsion is powered by storable toxic propellants or by cryogenic combinations.

Research Objectives:

1. Assessment of green propellants w.r.t. performance characteristics & material compatibility.
2. Assessment of liquid green propellant technologies (GPTs) for monopropellant systems for ACS.
3. Assessment of liquid GPTs for bipropellant systems for stages.

Expected Results:

1. Clear identification of the requirements of the propulsion system for green propellant ACSs and stages.
2. Preliminary design of the down selected monopropellant and bipropellant thrusters.
3. Ground testing of the selected thrusters.

• Host institution:
  Università di Roma La Sapienza
• Main Supervisor:
  Prof. Daniele Bianchi
  
• Enrolment:
  Università di Roma La Sapienza

Problem Definition: ANCs can improve the design and performance of launch vehicles. The best ANC solution is closely related to the overall launcher design. However, a practical approach able to quickly and safely design optimized ANC basing on the overall launcher architectural and mission constraints has not yet been developed.

Research Objectives:

1. Analysing the design criteria, flow characteristics and expansion efficiency at different working conditions - using combined engineering approaches, system analysis and CFD simulations - of conventional over-expanded nozzle, dual-bell nozzle & aerospike nozzle design.
2. Defining a system level design methodology for these advanced nozzle configurations with respect to conventional ones, based on various requirements tailored on specific mission-based applications (e.g. reusable/expendable launcher, first/upper stage).

Expected Results:

1. Computed performance gains with respect to conventional configurations.
2. Validation and calibration of models included in CFD simulations based on available experimental data (cold-flow sub-scale tests).
3. Definition of a system level design methodology for the advanced nozzle configurations under study with respect to conventional ones.

• Host institution:
  ONERA
• Main Supervisor:
  Dr. François Chedevergne
  
• Enrolment:
  ISAE-SUPAERO

Problem Definition: The capability to predict aerodynamic forces, moments and wall heat fluxes for various shapes & physical phenomena encountered during re-entry is of particular importance for RLV, but also for safe disposal of upper stages.

Research Objectives:

1. Validating the CFD simulations of the critical physical phenomena induced by reusable launchers concepts using ONERA’s in-house multi-physics solver (CEDRE) for energetic & propulsion simulations.
2. Building & analysing an exhaustive ATDs database for future launcher concepts defined by ESR3 & for flight points extracted from the optimised trajectory defined by ESR14.
3. Developing & validating analytical models able to predict aerodynamic coefficients & wall heat fluxes for multiple trajectories using the CFD database.

Expected Results:

1. Validated CFD simulations of the critical physical phenomena.
2. An exhaustive ATDs database and its analysis.
3. Analytical models predicting aerodynamic coefficients and wall heat fluxes for multiple trajectories.

• Host institution:
  ONERA
• Main Supervisor:
  Dr. Jouke Hijlkema
  
• Enrolment:
  ISAE-SUPAERO

Problem Definition: HREs have been investigated through lab-scale firing tests and numerical simulations, from 1D representations of the complete engine to detailed yet complex 3D and time resolved simulations of the internal combustion chamber geometry. These approaches do not allow the understanding of the complete engine behaviour and maturing the technology.

Research Objectives:

1. Improve the 1D modelling code to predict the propulsive performance of the HRE complete system in support of the firing test data analysis of ESR9.
2. Design an optimized HRE combustion chamber for keeping the oxidizer to fuel ratio as constant as possible (for high and constant propulsive performance) while reducing the residual inert mass.

Expected Results:

1. Improved and validated 1D modelling code for HRE performance using static firing tests performed by ESR9.
2. Detailed 2D/3D CFD computations of the HRE combustion chamber using the CEDRE multi-physics solver.
3. Design of the optimized combustion chamber geometry by coupling 1D and 2D/3D computations.
4. Performance assessment of the optimized solution by performing the corresponding firing tests at ULB-ATM with ESR9.

• Host institution:
  Université libre de Bruxelles
• Main Supervisor:
  Prof. Patrick Hendrick
  
• Enrolment:
  Université libre de Bruxelles

Problem Definition: HREs could replace existing bi-liquid engines for new applications such as nano-launchers or orbital insertion of multiple payloads in various orbits as HREs offer much lower costs and large throttle ability. Drawbacks are related to the difficult to control oxidizer to fuel ratio during operation and to the residual inert mass.

Research Objectives:

1. Improve in situ measurements of the regression rate using the two existing test facilities (one with optical access) of ULB-ATM.
2. Development of the experimental data base obtained using various injection heads / systems.
3. Generate validated experimental data for HRE using N20 as an oxidizer and paraffin or polyethylene as a fuel in support of the numerical simulation activities of ESR8.

Expected Results:

1. Validated and instrumented test facilities for sea level operated complete HREs.
2. A robust technology to measure in situ the high regression rate of the fuel in these HRE.
3. A database of validated experimental results with paraffin-fuelled HRE.
4. Performance data restitution of all HRE experiments by performing the corresponding 1D computations at ONERA with ESR8.

• Host institution:
  Hochschule Bremen
• Main Supervisor:
  Prof. Uwe Apel
  
• Enrolment:
  Technische Universität Dresden

Problem Definition: Current low to medium specific impulse upper stage propulsion systems are all pressure fed because conventional turbopump systems do not offer advantages in performance and cost at low engine pressure levels. Electrical pump-feeding will allow to keep the overall performance of current propulsion systems using green propellants at moderate cost burden.

Research Objectives:

1. System performance analysis of electric pump feeding compared to pressure feeding.
2. Preliminary system design of an H2O2 / ethanol propulsion system.
3. Detailed design of electrical H2O2 and Ethanol pump subsystem.
4. Experimental verification of electrical pump system under laboratory conditions.
5. Operation of electrical pump system on test engine at HSB test stand

Expected Results:

1. Establishment of a preliminary design of a propulsion system in the 400 N class.
2. Overall design and performance simulation model for all subsystems.
3. Detailed design of the electric pump subsystem.
4. Laboratory test results showing characteristics and performance of the electric pump feeding system.
5. Test results of propulsion system with electric pump feeding

• Host institution:
  Università di Pisa
• Main Supervisor:
  Prof. Angelo Pasini
  
• Enrolment:
  Università di Pisa

Problem Definition: One ESR is dedicated to the overall system design of upper stages due to the complexity of upper stage design aspects including the development of green propulsion systems, electric pump-feeding and HRE’s as well as the adherence to safe disposal requirements and novel GNC solutions for injecting multiple payloads to different orbits.

Research Objectives:

1. Identification of relevant mission profiles of future launchers.
2. Identification of requirements for green expendable upper stages of future launchers compliant with the space debris mitigation guidelines.
3. Preliminary design of the upper stage with focus on attainable propulsive performance and affordable envelope and mass budgets.
4. Preliminary design of the propulsion system of the upper stage.
5. Detailed design of the propulsion system of the upper stage with focus on most critical components.

Expected Results:

1. Definition of the requirements for upper stages of future launchers.
2. Recommendation of green propellant technologies for future substitution of current upper stage powered by toxic propellants.
3. Upper stage design to enable space access for multiple payloads.
4. Upper stage design for lower orbit to GTO of Reusable Two Stage To Orbit launchers.

• Host institution:
  Technische Universität Braunschweig
• Main Supervisor:
  Prof. Enrico Stoll
  
• Enrolment:
  Technische Universität Braunschweig

Problem Definition: Determining the exact place and time of re-entries is still challenging because different uncertainties need to be considered. In today’s launcher development, very conservative methods like combinatorial reliability are applied for reliability calculation. This frequently leads to masses and costs higher than necessary.

Research Objectives:

1. Developing a new reliability model for rocket flight with special focus on re-entry by transferring existing reliability methods to launcher concepts defined by ESR3.
2. Implementing a software or software component that can determine re-entry prediction for new rocket concepts based on mission designs investigated by ESR15.
3. Considering space situational awareness aspects, such as propagation with uncertainties, the space debris flux, and collision probabilities within the software.
4. Investigating new concepts that enhance or allow a safe disposal, such as green propellants, passivation, enhanced break-up or advantageous orbits.

Expected Results:

1. Recommendation of sustainable and reliable rocket concepts based on most suitable technology and mission concepts.
2. Verification of their safe disposal by the reliability model and precise trajectory software.

• Host institution:
  Politecnico di Milano
• Main Supervisor:
  Prof. Michèle Lavagna
  
• Enrolment:
  Politecnico di Milano

Problem Definition: While single orbit injection is the routine, multiple platforms in orbit insertion is available but the secondary payloads have to accept the injection in the main satellite trajectory neighbourhood. Thus, multiple platform injections in dedicated and different trajectories with high level of accuracy need novel GNC designs.

Research Objectives:

1. Identifying GNC solutions, which increase the launchers flexibility in terms of reachable final conditions.
2. Modelling of the complex nonlinear & coupled dynamics of a multi-stage vehicle.
3. Tuning of nonlinear dynamics control for the whole launcher stages history to minimize the fuel consumption to insertion & maximize different satellite cluster insertion feasibility, mission dependent.
4. Taking into account the potential different propulsive solutions analysed in WP2-3 for identification of optimal control strategies.

Expected Results: The optimal GNC and path planning strategy for future launchers design, depending on the propulsion architecture, ensuring a large reusability and flexibility with respect to the range of the orbital insertion conditions requests.

• Host institution:
  Politecnico di Milano
• Main Supervisor:
  Prof. Michèle Lavagna
  
• Enrolment:
  Politecnico di Milano

Problem Definition: Re-entry, descent and precision soft landing in atmosphere is very challenging. Europe has no flown experience for such launcher elements. The atmosphere presence demands nonlinear and robust control strategies to cope with the non-linearities and numerous uncertainties to be identified and implemented in the simulation software. Retargeting performance is envisaged as well.

Research Objectives:

1. Identification of requisites for a launcher component to be softly and precisely re-entered, depending on its configuration, initial state conditions & safety boxes requirements.
2. Developing a 6DOF re-entry dynamics model with uncertainties in specific parameters (ballistic coefficient, atmosphere density, etc.).
3. Implementation of robust & adaptive control for compliance with final imposed conditions.
4. Assessment of the level of reusability w.r.t. the dynamics control complexity according to the different multidisciplinary aspects.

Expected Results: A tool to synthesize robust GNC for unmanned atmospheric re-entry vehicles under precision and soft landing constraints, depending on the specification of the vehicle itself and its dynamical conditions.

• Host institution:
  Deimos Space
• Main Supervisor:
  Mr. Davide Bonetti
  
• Enrolment:
  Politecnico di Milano

Problem Definition: A key challenge of reusable re-entry systems with multiple flight capabilities is the missionisation of the vehicle’s MA and GNC, which refers to both the recurrent activity to tailor the MA and GNC solution for the vehicle for one particular mission and also the capability of providing a single solution that is qualified for multiple landing sites.

Research Objectives:

1. Developing a clear and efficient missionisation process for re-entry vehicles.
2. Identifying and investigating the different missionisation problems and challenges for current and future re-entry vehicle missions and GNC systems.
3. Identifying different approaches and techniques for efficient re-entry trajectory and GNC missionisation, both to tailor the MA and GNC solution for one particular mission and providing a single MA and GNC solution that is qualified for multiple landing sites (e.g. primary and back-up).
4. Developing a MA and GNC missionisation strategy, process and tool for use in future European re-entry vehicle activities.

Expected Results:

1. An understanding of the trade-space for re-entry vehicle MA & GNC missionisation w.r.t. that for launchers.
2. Definition of a re-entry vehicle MA & GNC missionisation process minimising the delta processes & effort to perform the missionisation between different missions / landing sites in one mission.
3. A re-entry vehicle MA & GNC missionisation tool that supports the efficient update of the mission solution (e.g. trajectory) & the GNC (e.g. its design & parameters) for each mission & supports the efficient verification of the GNC solution.
4. The application & validation of the process & tools on a representative study case scenario, performed using a 3 / 6 DOF simulator.