Flight Dynamics Evaluation for the T3 Suborbital Flight Test
Deimos Engineering and Systems; Gutierrez Briceño, Jaime; Medici, Giovanni; Princi, Alessandro; De Zaiacomo, Gabriele
- Publisher
- Zenodo
- Language
- en
Abstract
Almost 10 years after the first successful landing of a Falcon 9 booster, reusability of first stages is still a feature that only SpaceX has been capable to master. Nevertheless, reusability is now part of the baseline design of several launch system currently under development, in the US and China. In this context, the SALTO project, funded by the European Commission and coordinated by ArianeGroup (AGS), aims to raise the maturity level of the first European reusable rocket technology. On one side SALTO will perform, for the first time in Europe, hop-flight tests of a small-scale reusable rocket first-stage demonstrator – named the T1H – to validate the landing phase. In parallel, key technologies will be developed to be integrated in the next suborbital flight vehicle – named the T3. In particular, the T3 will be a large-scale demonstrator that will fly at very high-altitude in the atmosphere and perform all the most relevant maneuvers that are needed to return and recover the first stage of a launcher. During the test mission, it will fully control its attitude making use of grid fins and thrust vector control. Deimos’ contribution to SALTO includes support to the aerodynamic design of the T3 taking the responsibility of the flight qualities analysis and of the control laws assessment for the suborbital test mission. The trimmability, stability and controllability of the vehicle is evaluated during the full flight envelope to support several iterations of the aerodynamic design. In addition, the feasibility of the suborbital mission is studied in detail and the trajectory optimized to increase the representativity of the suborbital flight test with respect to dynamic conditions that a reusable booster will have to face during the return path. Finally, Deimos will also continue the development of state-of-the-art control laws initially developed in the RETALT project and adapted to the T3 scenario, that are being tailored to the suborbital mission and will be tested up to TRL 5. Funded by the European Union under the grant agreement ID 101082007. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. Index Terms—launchers reusability, flight mechanics, re-entry trajectory, SALTO.
Full text
FLIGHT DYNAMICS EVALUATION FOR THE T3 SUBORBITAL FLIGHT TEST 20/05/2025 Jaime Gutiérrez, Giovanni Medici, Alessandro Princi, Gabriele De Zaiacomo 3rd International Conference on Flight vehicles, Aerothermodynamics and Re-Entry
Agenda 2 1. Project overview 2. Reference configuration 3. Mission feasibility analysis 4. Post-MECO flight dynamics analysis 5. Grid fins control strategy 6. Entry corridor analysis 7. Reference trajectory update 8. Conclusions and way forward
SALTO overview •SALTO - reusable Strategic Space Launcher Technologies & Operations •Funded by the European Union in the frame of the Horizon Europe programme •Supports the ESA Themis programme •T1H hop tests •Technology maturation for T3 and future launcher configurations 3
SALTO overview 4
Reference configuration 5 45.8% 49.1% 54.0 % T3 FALCON 9 RETALT T3 configuration: •~30m-tall large-scale model of 1st stage of a VTVL heavy launcher •Integrates 3 Prometheus engines •~24 tons dry mass, ~55 tons propellant T3 FALCON 9 RETALT
Reference configuration 6 AEDB 1.0, four configurations, implemented1, inspected, and verified with the AoA-polar provided. FFN-N UFN-P UF1-P UF2-P 1Marwege A. et al., Building an Aerodynamic Model of a Vertical Landing Reusable Launcher Based on CFD and Wind Tunnel Experiments in SALTO and CFD4SALTO, 3rd FAR conference, Arcachon, France, 2025
Mission feasibility analysis 7 T3 FALCON 9 RETALT ArianeNext, F9 and RETALT are expected to be relatively similar launchers in terms of payload capacity. Geometric differences are mainly due to the choice of propellant. Therefore, the 1st stage of these launchers are expected to fly relatively similar trajectories. Launcher Payload to LEO Payload to GTO Falcon 9 1 22.8 t (expendable) 17.5 7 (DRL) 8.3 t (expendable) 5.5 t/3.5 t (DRL/RTLS) RETALT 20 t (DRL/RTLS) - Ariane Next 2 - >7 t (expendable) >4.5 t (DRL) 1Capabilities and Services. SpaceX. 2024 2Patureau de Mirand, A. et al (July 2019). Ariane Next, a vision for a reusable cost-efficient European rocket. 8th EUCASS. doi:10.13009/EUCASS2019-949
Mission feasibility analysis 8 T3 FALCON 9 RETALT T3 MECO R2 R3 T3 MECO
Mission feasibility analysis 9
1. Assuming that no partial MECO is performed, and trying to reproduce ArianeGroup’s original reference. 2. Assuming that partial MECO is performed, turning off two of the three engines when the altitude reaches 20 km. Reference trajectory update 16 Trajectory updated needed due to new Prometheus model, updated AEDB 1.1, and lessons learned from previous analyses. Two further assumptions are injected to update the reference trajectory:
Reference trajectory update 17
Reference trajectory update 18
Conclusions and way forward 19 •The mission engineering activities demonstrated that the suborbital flight test of the T3 vehicle is feasible and could also guarantee an adequate representativity of the expected operational conditions. •An analysis methodology was introduced to define and evaluate performance maps for the flight test and support the identification on promising design points. •The baseline mission identified was consolidated and verified in full alignment with the most detailed vehicles models made available during the activity. •The assessment of the capabilities of the proposed configuration is supporting the consolidation of the aerodynamic characterisation of the T3 vehicle, currently ongoing in the framework of SALTO. •Moreover, the flight dynamics evaluation is supporting also the consolidation of control laws1 that will be evaluated considering also uncertainties and dispersions: •Testing will be performed with Model-in-the-Loop (MIL), Software-in-the-Loop (SIL), and Processor-in-the-Loop (PIL) approaches with the goal of reaching TRL ≤ 5 at the end of the activity. 1Guadagnini J., De Zaiacomo G., et al., End-to-end GCN Solution for Reusable Launch Vehicles, MDPI Aerospace Journal special issue on Modelling, Simulation and Control of Launch Vehicles, 2025.
Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or European Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. Thank you!
