Cranfield Space Research Centre Cranfield University Formation Flying Research

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Cranfield Space Research CentreCranfield
UniversityFormation Flying Research
Prepared by Dr Jenny Roberts
Research Fellow Space Research Centre
Cranfield University
j.a.roberts_at_cranfield.ac.uk
RT Workshop, RCDS, 23 Feb 2006
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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.

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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

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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

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MUSTANG

• Research and development has continued
• Structures are available
• Dynamics and control algorithms verified
• End-of-life technologies developed

J2-Invariant Relative Orbit (J.Roberts PhD, 2005)
MUSTANG Inter-satellite Release Mechanisms
(E.Allouis MSc, 2002)
Orbit Propagator (B.Marchand, MSc, 2005)
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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).

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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

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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

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Current Research

• LEO Formation Flying Dynamics and Control
• Detailed analyses of relative dynamics in the
  presence of disturbances (particularly J2)

• 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 ?V136ms-1
Controlling Accelerations
Axes
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Current Research

• Formation Flying Dynamics and Control at L2

• Detailed analyses of relative dynamics around a
  halo reference orbit at the Sun-Earth L2 point

• 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

• mN thrust for formation rotation
• µN thrust for station keeping