INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL Int. J. Robust Nonlinear Control 2002; 12:207–242 (DOI: 10.1002 /rnc.683) Co-ordination and control of distributed spacecraft systems using convex optimization techniques Michael Tillerson 1,y,} , Gokhan Inalhan 2,z,k and Jonathan P. How 1, * ,}, ** 1 Department of Aeronautics and Astronautics, MIT, USA 2 Department of Aeronautics and Astronautics, Stanford University, USA SUMMARY Formation flying of multiple spacecraft is an enabling technology for many future space science missions. However, the co-ordination and control of these instruments poses many difficult design challenges. This paper presents fuel/time-optimal control algorithms for a co-ordination and control architecture that was designed for a fleet of spacecraft. This architecture includes low-level formation-keeping algorithms and a high-level fleet planner that creates trajectories to re-size or re-target the formation. The trajectory and formation-keeping optimization algorithms are based on the solutions of linear and integer programming problems. The result is a very flexible optimization framework that can be used off-line to analyse various aspects of the mission design and in real time as part of an onboard autonomous formation flying control system. The overall control approach is demonstrated using a nonlinear simulation environment that includes realistic measurement noises, disturbances, and actuator nonlinearities. Copyright # 2002 John Wiley & Sons, Ltd. KEY WORDS: formation flying control; distributed spacecraft systems; real-time trajectory optimization; linear programming 1. INTRODUCTION Formation flying of multiple spacecraft is an enabling technology for many future space science missions including enhanced stellar optical interferometers and virtual platforms for earth observations. This approach will use a distributed array of simple but highly co-ordinated microsatellites to form a ‘virtual satellite bus’ that replaces the standard monoliths used today Copyright # 2002 John Wiley & Sons, Ltd. *Correspondence to: Jonathan P. How, Dept. of Aeronautics and Astronautics, MIT, U.S.A. y Research Assistant z Research Assistant } Associate Professor } E-mail: mike_t@mit.edu k E-mail: ginalhan@leland.stanford.edu ** E-mail: jhow@mit.edu Contract/grant sponsor: AIR FORCE; contract/grant number: F49620-99-1-0095 Contract/grant sponsor: NASA GSFC; contract/grant number: NAG5-6233-0005