Importance of Optimisation in Space Missions

Transcription

1 Importance of Optimisation in Space Missions Celia Yabar 3 rd OSE Workshop 17/09/2015

2 Outline 1. ESA and its missions 2. Optimisation in space missions 3. Current optimisation challenges 4. Optimisation tools and techniques developed in the GNC section at ESA 5. Summary & Conclusions Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 2

3 ESA and its missions

4 About ESA and its programs The European Space Agency (ESA) is Europe s gateway to space. Its mission is to shape the development of Europe s space capability and ensure that investment in space continues to deliver benefits to the citizens of Europe and the world ESA is an international organization with 22 Member States ESA activities: Observing the Earth Human Spaceflight Launchers Navigation Space Science Space Engineering Operations Technology Telecommunications Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 4

5 Past ESA missions Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 5

6 Current and future ESA missions Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 6

7 Guidance Navigation and Control at ESA TEC-ECN Section (GNC Section) Where are we inside ESA? Directorate of Technical & Quality Management Electrical Engineering Department Control Systems division Guidance Navigation and Control section What do we do? Support ESA projects in the areas of GNC Manage and technical monitoring of R&D contracts Support to Concurrent Design Facility studies as GNC experts Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 7

8 Optimisation in space missions

9 Importance of Optimisation in Space Optimality is essential due to the exponential nature of the launcher propellant requirements with respect to payload mass and achievable destination Consideration of key mission objectives together with other crucial aspects such as technical feasibility, cost-efficiency and mission safety Space missions require the analysis and optimisation of trajectories, fuel consumption, cargo handling, subsystems design and many others Space missions are continuously becoming more complex requiring the solution of increasingly hard optimisation problems Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 9

10 Optimisation areas Many areas where optimisation is interesting: 1. Mission analysis and trajectory planning 2. Planning and scheduling 3. Cargo loading and unloading 4. Payload accommodation 5. System design 6. Subsystem design 7. Ergonomic aspects 8. Payload performance 9. Observation data handling and remote monitoring 10.Cost and revenue management Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 10

11 Example Optimisation Areas (1/2) Mission analysis and trajectory planning Reduce overall mission expenses and improve mission effectiveness Minimize propellant to enhance launch vehicle capabilities Minimize time, especially for future manned interplanetary missions Planning and scheduling Minimize risks and cost of the mission ISS permanent logistic support and on-orbit resources supply Quick re-scheduling when off-nominal scenarios Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 11

12 Example Optimisation Areas (2/2) Cargo loading and unloading Optimize loading space and packing, object geometries Cargo accommodation inside ATV: mass and volume limitations, positioning rules, balancing conditions System design The subsystem-specific optimisation objectives may be in conflict when considered jointly. Need to find an overall (globally) satisfactory solution. Multidisciplinary and multi-objective optimisation Subsystem design Optimisation problems associated to a systems design structural, thermal, avionic, power, navigation, control, Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 12

13 Optimisation challenges in current missions

14 Science mission: JUICE Jupiter Icy moons Explorer (JUICE): Europe s first mission to the Jupiter system. It will make detailed observations of Jupiter and 3 of its largest moons, Ganymede, Calisto and Europa Problem: Optimisation of the interplanetary trajectory to visit all Jupiter Moons in a minimum time with minimum fuel and maximum payload. Difficult problem mostly because of many local minimums Current solution: local optimisation by segments Optimal Solution: Global optimisation techniques Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 14

15 Science mission: CHEOPS CHaracterising ExOPlanet Satellite (CHEOPS) Dedicated to searching for exoplanetary transits by performing ultra-high precision photometry on bright stars already known to host planets Problem: ultra-high precision photometry requires ultra-high pointing accuracy Current solution: Classical control (PIDs) Optimal Solution: Robust optimal control Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 15

16 NEO space mission: AIDA (DART + AIM) Double Asteroid Redirection Test (DART-NASA): Modify the trajectory of the secondary asteroid of the Didymos binary system Asteroid Impact Mission (AIM) Rendezvous and characterisation of the asteroid system Problem: Map the complete binary system before the impact using a high resolution camera minimizing the time and fuel consumption Optimal Solution: Global optimisation for optimal mapping Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 16

17 Exploration missions: PHOOTPRINT European Phobos Sample return mission (PHOOTPRINT) Sample return of the moon of Mars Phobos. Science characterisation, landing, sample acquisition and return to the Earth with a re-entry capsule Problem: Enable autonomous flight that can automatically recover from unexpected problems: failures, abort scenarios, landing site change, Current Solution: Ground in the loop Navigation and trajectory planning Optimal Solution: Real-time trajectory optimisation Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 17

18 Launchers (1) Design of a new launch vehicle Problem: The design of a new launch vehicles is a very complex task. Need of an optimized configuration that yields sufficient payload performance at minimum cost Current solution: iterative process during which experts from various disciplines refine and update their subsystem designs until they converge to a consistent, good design Optimal solution: tackle the problem as a multi-disciplinary design optimisation (MDO) and avoid decomposing the system Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 18

19 Launchers (2) VEGA launcher roll control Problem: The presence of roll during the first stage of the VEGA Launcher vehicle, which needs to be controlled. The causes of roll are: - Roll torque induced by geometrical imperfections - Roll torque induced by the combustion - Aerodynamics and winds Current solution: classical control design + extensive validation campaign Optimal solution: use of H-infinity optimized methods to reduce development cost and guarantee robustness by design Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 19

20 Launchers (3) V&V analysis to guarantee the mission s safety The stability and performance must be assessed for nominal as well as including uncertainty in mission parameters Problem: determine the combination of uncertain parameters that leads to the worst case performance violation Current solution: Traditional Monte Carlo campaigns (randomly sampling the uncertain parameters according to statistical distributions) Optimal solution: Identify the uncertain parameter combination which provides extremum values of a given performance criterion by employing different local, global and hybrid optimisation methods. Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 20

21 GALILEO constellation GALILEO constellation Europe s own global satellite navigation system 30 satellites in MEO (10 satellites /orbital plane, 56 inclination) Problem: Need for an efficient satellite constellation management plan including strategies for launch, set-up and replacement Optimal solution: global optimisation to define the best deployment strategy minimizing cost and time Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 21

22 Telecommunications: ELECTRA Program Electra Program: A full electric-propulsion telecommunications satellite in the 3-tonne launch mass range Problem: replacing the apogee kick-engine by Electric Propulsion for transfer from injection orbit to GEO requires an optimized low thrust trajectory Optimal solution: high-fidelity optimisation of electric propulsion orbit raising manoeuvres Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 22

23 Optimisation tools and techniques developed by the TEC-ECN section

24 Optimisation tools and techniques (1) WORHP: We optimize really huge problems European Mathematical NLP Solver. Tool for solving large-scale, sparse, nonlinear optimisation problems with millions of variables and constraints (Uni Bremen, Uni Southampton, Uni Coimbra, Astos Solutions) Extension of WORHP to multi- and many-core Architectures (Steinbeis Forschungszentrum) Enhancement of WORHP using Parametric Sensitivity Analysis with respect to Hessian regularization and constraint relaxation (2015,TBC) MIDACO solver: Mixed Integer Distributed Ant Colony Optimisation (Airbus) Solver for general optimisation problems that can be applied to continuous (NLP), discrete/integer (IP) and mixed integer (MINLP) problems Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 24

25 Optimisation tools and techniques (2) Global optimisation Assessment of global optimisation mathematical methods for space engineering (University of Southampton) Filtering techniques (University of Southampton, Coimbra and Birmingham) Versatility of Filtering Techniques in Non-Linear Programming Optimisation FGS: Filtering and globalization strategies toolbox MCO (Multiple Cost Optimisation) Add-On for the FGS Toolbox Filtering Uses the same concept of multiple filters to have multiple objectives (costs) Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 25

26 Optimisation tools and techniques (3) Trajectory optimisation ASTOS Frame Contract (upgrade and update of optimisation capabilities) AeroSpace Trajectory Optimisation Software (Astos Solutions) Development of the Hybrid Transcription Method CAMTOS (Astos Solutions) Hybrid optimizer which allows the choice of collocation and multiple shooting at each phase Development of PROMIS / TROPIC (DLR) Trajectory optimization using direct collocation (TROPIC) Parameterized trajectory optimization by direct multiple shooting (PROMIS) Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 26

27 Optimisation tools and techniques (4) Optimisation of NS/EW Station-Keeping Manoeuvres for GEO Satellites using Electric Propulsion (GMV & Airbus) Multi-Disciplinary Optimisation for Launchers and Reentry Vehicles (ASTOS, RUAG) Electric Propulsion Orbit Raising Analysis and Optimisation Tool (ASTOS & GMV) Worse case Analysis Tool WCAT (University of Exeter) LPV modeling analysis and design (LPVMAD, Deimos Space) PhDs Prestige Program: Multi-disciplinary design optimisation for space vehicles (Bremen University, Politecnico di Milano) NPI Program: Multi-objective hybrid optimal control problems (Strathclyde University & Airbus, on-going) Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 27

28 Possible collaborations Technology research and development programs TRP: Basic Technology Research Programme GSTP: General Support Technology Programme NPI: Network/Partnering Initiative ITI: Innovation Triangle Initiative Assessment TEC-ECN Information Part of ESA s mandatory Basic Activities The backbone of ESA s innovation effort covering up to proofof-concept TRL 3 50 M in industrial contracts per Year, 150 contracts per year Covering all technology disciplines and applications except Telecommunications (covered by the ARTES programmes) Ensures that the right technology with the right maturity are available at the right time M in industrial contracts per Year, activities Innovative doctoral or post-doctoral proposals with the collaboration of research institutes, universities and industry Requires the collaboration of 3 different entities: Inventor, developer and customer Part of TRP budget (4 M ) ECN Engineering Support Tools and Assessment activities Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 28

29 Summary and Conclusions Optimisation is indispensable in many different aspects of any space mission Space missions are continuously becoming more complex requiring the solution of increasingly hard optimisation problems Collaboration between ESA, industry and academia is essential to continue innovating regarding both theoretical advances and ready-to-use tools for actual applications Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 29

30 Thank you! Importance of Optimisation in Space Missions Celia Yabar 17/09/2015 Slide 30