Cranfield Space Research CentreCranfield UniversityFormation Flying Research: Cranfield Space Research Centre Cranfield University Formation Flying Research R&T Workshop, RCDS, 23 Feb 2006 Prepared by: Dr Jenny Roberts Research Fellow Space Research Centre Cranfield University j.a.roberts@cranfield.ac.uk


Space Research Centre: Space Research Centre Cranfield Space Research Centre staff teach and research in a wide range of topics related to space engineering, space systems and space applications. We have around 300 alumni, and work closely with key companies and other organisations in the space industry.


Space Research Centre : Space Research Centre Distributed Space Systems is the common theme of most current projects, and includes interests in spacecraft design, miniaturisation, formation flying, applications, and end-of-life technologies relevant to space debris. Cranfield Space Research Centre (CSRC) staff are involved with and are able to draw upon wider university research in flight dynamics and UAV design and operation. Flight dynamics and control Test bed development Links into CSRC research: Aerobot design for space applications Formation flying algorithm design and test


MUSTANG: MUSTANG MUSTANG: Multi-University Space Technology Advanced Nano-satellite Group BNSC funded project, 2001 Joint programme with University of Southampton, with Astrium supporting Objective: To develop technologies for formation flying and related spacecraft miniaturisation


MUSTANG: MUSTANG Research and development has continued Structures are available Dynamics and control algorithms verified End-of-life technologies developed MUSTANG Inter-satellite Release Mechanisms (E.Allouis MSc, 2002) J2-Invariant Relative Orbit (J.Roberts PhD, 2005) Orbit Propagator (B.Marchand, MSc, 2005)


Past Formation Flying Studies: Past Formation Flying Studies Past MSc and PhD Research Theses 1996-2005 Control of Collocated Geostationary Satellites (S.Hardacre, PhD, 1996). Drag-Free Control and Technological Risk Assessment for the LISA Gravitational Wave Space Antenna (P.Roberts, EngD, 2000). Optimal Control of a Formation Flying Group of Spacecraft (D.Jarraud, MSc, 2001). Sliding Mode Satellite Formation Control with Application to XEUS (D.Deering, MSc, 2002). Formation Flying for MUSTANG (D.Izzo, GDP, MSc, 2002). Development of a Formation Flying Model for Satellites in Elliptical Orbits (D.Curtis, MSc, 2003). FEEP Thruster Nano-Satellite Applications (W.Fernando, PhD, 2004) Development of a MATLAB Orbit Propogator (LEO Formation Design Tool) (B.Marchand, MSc, 2005). Satellite Formation Flying for an Interferometry Mission (J.Roberts, PhD, 2005).


Current Formation Flying Studies: Current Formation Flying Studies Current Thesis Research Topics Mission Design Conceptual Design of an Extrasolar Planet Observation Mission (PROBA-3) A Small Scale Magnetospheric Constellation Mission (SciSys sponsorship) Rendezvous Analysis and Applications Formation Flying Dynamics and Control Research Investigation of the Effects of Sensors/Actuators on Precision Formation Flying GNC for the Darwin Mission (EADS Astrium and ESA sponsorship) Research Tool Development and Application Development of a Matlab Formation Flying Simulation Tool (High fidelity tool now in 3rd year of in-house development) Development of a Flying Testbed Control Strategies in Formation Flying Martian Aerobots (SciSys sponsorship) Car-to-Car GNSS Relative Positioning Algorithm (VEGA) Aerobot/Robot Video Navigation


FF Related Contract Research: FF Related Contract Research 2001 MUSTANG Contract for BNSC 2003 Contract for ESA The Development of a High Fidelity Linearised J2 Model for Satellite Formation Flying Control Dynamics model development and Verification Control system design 2006 PhD funding from ESA and EADS Astrium Formation Guidance and Control for Darwin Global fuel use minimisation strategies Solution of multi-manoeuvre and reconfiguration problems while balancing fuel use across the formation


Current Research : Current Research LEO Formation Flying Dynamics and Control Detailed analyses of relative dynamics in the presence of disturbances (particularly J2) Controlling Accelerations Development of constant coefficient and time varying equations Design of fuel-minimising orbits and relative trajectories Application of new dynamics models to control system design Identification of orbits which are able to reduce fuel consumption by over 25% for a close formation, continuously controlled in LEO Circular Relative Orbit Station-Keeping ΔV=136ms-1 Axes


Current Research : Current Research Formation Flying Dynamics and Control at L2 Development of constant coefficient and time varying equations Controlled manoeuvre simulation and evaluation in the perturbed environment for a Darwin-type mission Fuel-Balancing guidance functions developed Detailed analyses of relative dynamics around a halo reference orbit at the Sun-Earth L2 point mN thrust for formation rotation μN thrust for station keeping