meetings - Space Flight Mechanics Committee

Feb 12, 2013 Kauai Salon 3
SESSION 15: DYNAMICAL SYSTEMS THEORY
Chair: Dr. Kathleen Howell, Purdue University
13:30 AAS Leveraging Resonant Orbit Manifolds to Design Transfers Between Libration
13-334 Point Orbits in Multi-body Regimes
Mar Vaquero, Purdue University; Kathleen Howell, Purdue University
Resonant orbits are widely employed in mission design for planetary flybys (JEO) and,
more recently, to support long-term stability (IBEX). Yet, resonant orbits have not been
explored as transfer mechanisms between non-resonant orbits in multi-body systems. Given
the increased interest in Libration Point Orbits (LPOs) for a large number of different
purposes, transfers from LEO to the Earth-Moon LPOs that leverage conic arcs and
invariant manifolds associated with resonant orbits and LPOs are investigated. Solutions are
generated in the three-body model and transitioned to a full ephemeris model. Optimization
techniques can further reduce propellant requirements.
13:50 AAS Tour Design Using Resonant Orbit Heteroclinic Connections in Patched
13-493 Circular Restricted Three-Body Problems
Rodney Anderson, NASA / Caltech JPL
It is increasingly desirable to incorporate multi-body effects in tour design early in the
process to make use of these effects and potentially discover new solutions. Flybys have
previously been designed using the heteroclinic connections of resonant orbits in the
circular restricted three-body problem (CRTBP), but tour design often requires the
consideration of additional moons, especially within the Jovian system. In this study,
heteroclinic connections of resonant orbits are chained together within separate CRTBP
models to perform multiple flybys that advance through desired resonances. Aspects of
patching these trajectories together are explored, and a sample trajectory is computed.
14:10 AAS Examining the Learning Rate in Iterative Learning Control Near the Start
13-336 and the End of the Desired Trajectory
Fei Gao, Tsinghua University; Richard Longman, Columbia University
Iterative learning control (ILC) can be used in spacecraft applications to make feedback
control systems performing repeated tracking maneuvers produce high precision tracking
accuracy. ILC laws have been developed that in a few iterations for learning improve the
tracking accuracy by a factor of 1000. This paper examines in detail the learning rate, and
finds that the learning near the start of the trajectory and near the end can be slow. Methods
a developed to address these issues, and also to produce a smart method to start the
iterations with the real world so that learning is accomplished more quickly.
14:30 AAS Linear State Representations for Discrete-Time Bilinear System Identification
13-337 by Interaction Matrices
Page 60
23 rd AAS / AIAA Space Flight Mechanics Meeting