1. SkyworkerAssembly, Inspection, and Maintenance of SSP Facilities Field Robotics Center December 8, 1999 William “Red” Whittaker Peter Staritz Chris Urmson

2. Space Solar Power Assembly, Inspection, and Maintenance (AIM) • Extensive structures • Kilometers in dimension • Millions of parts • SSP environment • Wide temperature range, sometimes exceeding 500K • Solar Proton Events • Galactic Cosmic Radiation • Microwave Radiation • Kilovolt buses • Long duration operations • 1 year construction • 30 years operation

3. Motivation for a Robotic Workforce • High, inaccessible orbit • Overwhelming EVA agenda • Millions of parts • 10’s of Millions of Manipulations • Long term operations • Harsh environment • Robots are expendable and repairable • Lower support costs

4. Assembly, Inspection, and Maintenance Tasks • 3D agile traversal of a truss structure • Pick up and place payloads at arbitrary locations and orientations • Carry payloads while walking, turning, and transitioning planes • Conduct calibration and inspection tasks • Connect power and communications cables • Cooperatively carry bulky, massive payloads • Perform tasks that require multiple robot collaboration Current Program Future Work

5. Possible Avenues • Free Flying Systems • Require expenditure of mass to move • Result in tons of spare fuel • Risky docking operations • Fixed Manipulators (e.g. shuttle & station) • Anchored to a hard point on the structure • Limited reach • Longer reach results in larger dynamic/reaction forces • Attached Mobile Manipulators (AMM) • No mass expenditure • “Unlimited” reach • Ability to “walk lightly” • Temporarily attach for working reaction forces • AMM is the archetype for SSP AIM

6. Skyworker Scope • Robot Prototype and Software Simulation • Demonstrate the viability of using robots for orbital construction • Prove the validity of using structure walkers for orbital AIM • Demonstrate SSP AIM relevant tasks using robotics • Simulate prospective SSP AIM robots and tasks

7. Skyworker • Self Contained • Continuous gait allows payload to move at constant velocity • Requires less energy • Exerts less stress on the structure (walks lightly) • Counterbalanced to emulate micro g • Onboard processor and distributed control network • Mass: ~35 kg • Dimensions: 3 m x .5 m x .1 m • 11 DOF

8. Skyworker Simulation • 3D visualization of SSP AIM activity • Allows study of operations, and scale effects • Kinematic models demonstrate extended operations • Coordinated operations • Long term, large scale tasks

9. Results to Date • Skyworker developed • Component testing complete • Simulation package operational • Concept to operation in 99 days

10. Demonstration • Prototype • Pick up and carry a model transmitting element the length of the truss, turn while carrying, couple the element to the structure • Perform a mock calibration • Demonstrate “walking lightly” • Simulation • Perform prototype robot tasks • Perform plane transition • Assemble a large scale construction utilizing multiple robots • Emphasis placed on system level activity • Current grippers and sensors are placeholders for future development

11. Development Team • Skyworker has been developed by a team of staff and students at CMU • William “Red” Whittaker • Chris Gaiser • Oren Laskin • Dewitt Latimer • Jason Messinger • Jonathan Samuel • Sarjoun Scaff • Peter Staritz • Chris Urmson • Tim Warneck • Will Wong

12. 11 10 8 9 5 3 6 2 4 7 1 Skyworker DOF