Periodic Reporting for period 1 - SALTO (reuSable strAtegic space Launcher Technologies & Operations)
Reporting period: 2022-12-01 to 2024-05-31
The overall objective of SALTO is to raise the maturity of reusable rockets technologies in Europe, in order to enable the fielding of a reusable launch fleet in the 2030s. Building on Themis activities and other R&D projects, SALTO pursues a double target: launch-cost reduction and environmental footprint improvement to the benefit of EU strategic space missions.
This objective will be achieved by i) managing a system vision for next generation European rockets (thus providing relevant inputs feeding technology or architecture works), ii) maturing individual critical technologies that are lacking in Europe, and iii) implementing an intensive test & learn path with scale-1 reusable vehicles test flights.
In the medium term, SALTO will contribute to Europe’s strategic autonomy in developing, deploying and using global space-based infrastructures, services applications and data. It will reinforce the EU’s independent capacity to access space, secure the autonomy of supply for critical technologies and equipment, and foster the EU's space sector competitiveness. Horizon Europe funding provided to SALTO, in line with the Space Strategy for Europe, will contribute to 1) providing support for R&D activities on access to space and 2) preparing future evolutions of the European reusable launcher roadmap and space programme.
This objective will be achieved by i) managing a system vision for next generation European rockets (thus providing relevant inputs feeding technology or architecture works), ii) maturing individual critical technologies that are lacking in Europe, and iii) implementing an intensive test & learn path with scale-1 reusable vehicles test flights.
In the medium term, SALTO will contribute to Europe’s strategic autonomy in developing, deploying and using global space-based infrastructures, services applications and data. It will reinforce the EU’s independent capacity to access space, secure the autonomy of supply for critical technologies and equipment, and foster the EU's space sector competitiveness. Horizon Europe funding provided to SALTO, in line with the Space Strategy for Europe, will contribute to 1) providing support for R&D activities on access to space and 2) preparing future evolutions of the European reusable launcher roadmap and space programme.
At system level (WP3), building of the activities started in the frame of Themis under ESA contract, the hop test campaign is being prepared and technical requirements for activities dedicated to maturing relevant technologies for the next Themis step (after SALTO) have been issued.
Technology maturation activities have been performed during the first period:
- Focusing on future launcher applicability (WP4), a mathematical formulation of the sizing of launchers considering reusability was developed. Concepts for the structural integration of landing legs and control surfaces were reviewed.
- Regarding aerodynamics and aerothermodynamics (WP5), the first loop of the aerodynamic design of the vehicle for the next phase after SALTO was performed. A first aerothermal and aerodynamic database was generated and gave important design input for the aeroshape.
- In WP6, several activities have been performed to prepare the next steps after SALTO: industrialization of ultra low-cost lightweight tank industrialization maturation and manufacturing a full scale prototype, investigation of low-cost bio-sources thermal protection and removable thermal back shield, design of low-cost Grid Fins Structure and Grid Fins Actuator System, development of a demonstrator of landing leg has been prepared for testing.
- On health monitoring and safety technologies (WP7), the structural health monitoring was advanced, the actuator health monitoring system was defined, the development of an algorithm for the health monitoring of the Hybrid Navigation System was started and the development of the Autonomous Flight Termination System was initiated.
- On avionics (WP8), definition of a preliminary On-board Avionics architecture for SALTO embarked experiments and start of design for the different building blocks.
- On propulsion technologies (WP10), design of autogenous pressurization solutions, attitude control system and green flip control systems has started.
Finally, the launch vehicle for the hop test campaign (WP9) and the ground systems necessary for the flight campaign (WP11) were adapted and prepared; work on the flight software has been done in order to prepare the flight of the launch vehicle.
Technology maturation activities have been performed during the first period:
- Focusing on future launcher applicability (WP4), a mathematical formulation of the sizing of launchers considering reusability was developed. Concepts for the structural integration of landing legs and control surfaces were reviewed.
- Regarding aerodynamics and aerothermodynamics (WP5), the first loop of the aerodynamic design of the vehicle for the next phase after SALTO was performed. A first aerothermal and aerodynamic database was generated and gave important design input for the aeroshape.
- In WP6, several activities have been performed to prepare the next steps after SALTO: industrialization of ultra low-cost lightweight tank industrialization maturation and manufacturing a full scale prototype, investigation of low-cost bio-sources thermal protection and removable thermal back shield, design of low-cost Grid Fins Structure and Grid Fins Actuator System, development of a demonstrator of landing leg has been prepared for testing.
- On health monitoring and safety technologies (WP7), the structural health monitoring was advanced, the actuator health monitoring system was defined, the development of an algorithm for the health monitoring of the Hybrid Navigation System was started and the development of the Autonomous Flight Termination System was initiated.
- On avionics (WP8), definition of a preliminary On-board Avionics architecture for SALTO embarked experiments and start of design for the different building blocks.
- On propulsion technologies (WP10), design of autogenous pressurization solutions, attitude control system and green flip control systems has started.
Finally, the launch vehicle for the hop test campaign (WP9) and the ground systems necessary for the flight campaign (WP11) were adapted and prepared; work on the flight software has been done in order to prepare the flight of the launch vehicle.
Key results of SALTO beyond the state of the art include:
- First loop of the aerodynamic design of the vehicle for the next phase after SALTO. Further iterations on design are needed.
- Preliminary design of low-cost, lightweight tank for the next phase after SALTO. Detailed design will be finalized, and components and parts will be procured for testing.
- Creation of aerothermal database used for the design phase.
- Manufacturing of low-cost bio-sourced thermal protection and removable back shield. This will be tested (in lab for thermal tests and during the hop test).
- Design of low-cost grid fins structure. Two prototypes will be built.
- Evaluation of landing systems design evolution. Stating and dynamic tests are ongoing.
- Study of structural health monitoring
- Development of a concept for health monitoring between flights. Verification will be performed based on flight data to be collected in SALTO.
- Definition of flight control software architecture. Validation of the software on simulator platform and hardware in the loop platform will be required.
- Development of guidance control algorithms. Fine-tuning of the algorithm is still necessary.
- Design of pressurization systems for propellant management. Tests will be performed.
- Design of propellant management systems. Tests will be performed.
- Design of attitude control system. Tests will be performed.
- Design of green flip control system. Iterations on the design are necessary.
- Adaptation and validation of ground support equipment which will be used during the flight campaign in SALTO.
- First loop of the aerodynamic design of the vehicle for the next phase after SALTO. Further iterations on design are needed.
- Preliminary design of low-cost, lightweight tank for the next phase after SALTO. Detailed design will be finalized, and components and parts will be procured for testing.
- Creation of aerothermal database used for the design phase.
- Manufacturing of low-cost bio-sourced thermal protection and removable back shield. This will be tested (in lab for thermal tests and during the hop test).
- Design of low-cost grid fins structure. Two prototypes will be built.
- Evaluation of landing systems design evolution. Stating and dynamic tests are ongoing.
- Study of structural health monitoring
- Development of a concept for health monitoring between flights. Verification will be performed based on flight data to be collected in SALTO.
- Definition of flight control software architecture. Validation of the software on simulator platform and hardware in the loop platform will be required.
- Development of guidance control algorithms. Fine-tuning of the algorithm is still necessary.
- Design of pressurization systems for propellant management. Tests will be performed.
- Design of propellant management systems. Tests will be performed.
- Design of attitude control system. Tests will be performed.
- Design of green flip control system. Iterations on the design are necessary.
- Adaptation and validation of ground support equipment which will be used during the flight campaign in SALTO.