| Summary: | Thesis: S.M., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, May, 2020 === Cataloged from student-submitted PDF version of thesis. === Includes bibliographical references (pages 60-68). === On-orbit assembly missions typically involve humans-in-the-loop and use large custom-built robotic arms designed to service existing modules. The concept of on-orbit robotic assembly of modularized CubeSat components supports use cases such as rapidly placing failed nodes within a constellation of satellites and monitoring damaged assets in Low Earth Orbit. Despite the recent proliferation of small satellites, there is a lack of planned demonstrations of spacecraft manufactured through the on-orbit assembly as well as the servicing of small satellites in space. Key gaps limiting in-space assembly of small satellites are (1) the lack of standardization of electromechanical CubeSat components for compatibility with commercial robotic assembly hardware, and (2) testing and modifying commercial robotic assembly hardware suitable for small satellite assembly for space operation. Working towards on-orbit robotic assembly, we report on progress addressing both gaps. === Toward gap (1), the lack of standardization of CubeSat components for compatibility with commercial robotic assembly hardware, we have developed a ground-based robotic assembly of a 1U CubeSat using modular components and Commercial-Off-The-Shelf (COTS) robot arms without humans-in-the-loop. Two 16 in x 7 in x 7 in dexterous robot arms, weighing 2 kg each, are shown to work together to grasp and assemble CubeSat components into a 1U CubeSat. We assess performance for a subset of five commercial robotic arm sensors and find the force-torque (FT) sensor as the most efficient sensor for use at the end-effector and brushless motors as the best sensor for use at other joints. We report on the feasibility of sensing and grasping CubeSat components robotically, while using Inverse Kinematics to target, position and maneuver the robot arms. === Addressing gap (2) in this work, solutions for adapting power-efficient COTS robot arms to assemble highly-capable radiation-tolerant CubeSats are examined. We also analyze the systems engineering process for in-space CubeSat robotic assembly systems. Lessons learned on thermal and power considerations for overheated motors and positioning errors were also encountered and resolved. We find that COTS robot arms with sustained throughput and processing efficiency have the potential to be cost-effective for future space missions. === by Ezinne Uzo-Okoro. === S.M. === S.M. Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences
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