Controlled Autonomous Proximity Technology with flUx pinning & Reconfiguration Experiments CAPTURE: David Bayard, Laura Jones, and Swati Mohan Jet Propulsion Laboratory California Institute of Technology Copyright 2014, California Institute of Technology. Government sponsorship acknowledged Clearance URS , CL# , valid for U.S. and foreign release

To advance an end-to-end autonomous rendezvous, docking, and reconfiguration capability to TRL 7 using small satellites CAPTURE Objective

docking rendezvous reconfiguration Demonstrate GNC algorithms and capabilities for autonomous rendezvous of a chaser to a target to within 10cm from 5km Mature the technology for a passively-stable capture and docking maneuver using flux-pinned interfaces Demonstrate reconfiguration of the control system to achieve consistent control performance through changing configurations 3 CAPTURE Core Technologies

4 CAPTURE Rendezvous Technology Precision 6 DOF close-proximity G&C Developed at JPL for ST6 Inspection/circumnavigation Autonomous rendezvous & docking guidance Vision-based spacecraft-relative navigation Real-time image-based feedback 12 DOF state estimation using inertial/relative measurements IMU, sun sensor, star tracker, camera, flash lidar Autonomous operations with minimal ground intervention Rendezvous & Docking Circumnavigation Reconfiguration

Flux Pinning: Equilibrium is set below critical temperature (~88K) Passive 6 DOF stability in a nonlinear potential well Natural stiffness and damping in up to 6 DOF Close proximity (~10s cm) Cryocooled Superconductor Disk Flux-Pinned Interface (FPI) 5 CAPTURE Docking Technology Docking with FPIs: Passive physics-based trajectory from solid-state mechanism Impact attenuation Misalignment Correction Electromagnet control Magnet Array

Cryocooled Superconductor Disk Flux-Pinned Interface (FPI) 6 CAPTURE Docking Technology Magnet Array Flux-Pinned Passively Stable “Potential Well”

Spectrum of reconfiguration methods based on a-priori information assumed 7 CAPTURE Reconfiguration Technology Parameterized Control System CompleteNo Information Gain Scheduled (TRL 9) Reference Online Model Calculation New Technology (TRL 5) Outer loop to monitor configuration No info about target or attachment needed prior to docking Beneficial when -New target for existing chaser -Autonomy decides on order of assembly -Minimizes ground development and testing for multi-target missions

8 Mission Demonstration +V-Bar +R-Bar Formation Flying (~100 m) Circumnavigation (~20m) (Football orbit) Autonomous Mission Elements Formation Flying Circumnavigation Close-Proximity Inspection Approach/Closing Docking with Flux Pinning Control Reconfiguration Close-Proximity Inspection (~5m) Approach (Forced V-bar) Docking with Flux Pinning Start Experiment (Co-elliptic) Reconfiguration

Importance to NASA/JPL 9 –Relative sizing between Chaser and Target are relevant –Docking requirements commensurate with Orbiting Sample capture –Realistic starting approach distance (~ 5 km) –Coordinated relative sensing (Flash Lidar and Camera) Mars Sample Capture –Demo level of autonomy that is useful for assembly far from Earth –AR&D algorithms with plume impingement assessed –Show control Chaser alone and Chaser+Target to equivalent accuracy –Soft capture, beneficial to telescope applications, demonstrated Telescope Assembly On Orbit On-Orbit Servicing –Soft capture tech to dock and move Targets without physical contact –Show control Chaser alone and Chaser+Target to equivalent accuracy