UC Berkeley

The continuing miniaturization of commercial electronics, micro-electromechanical systems (MEMS), and low-mass spacecraft hardware has created an opportunity to reconsider how interplanetary science missions can be designed, manufactured, and deployed. Conventional spacecraft have enabled extraordinary planetary-science returns, but their high cost, long development cycles, and large system masses limit the number of targets that can be explored. This dissertation presents a MEMS-enabled femtoscale solar-sail spacecraft architecture intended to support low-cost asteroidal imaging, small-body reconnaissance, and future cometary sample-capture missions. The central spacecraft concept developed in this work is the Berkeley Low-cost Interplanetary Solar Sail (BLISS), a nearly 10 g solar-sail spacecraft that uses a roughly 1 m$^2$ reflective sail, commercial-off-the-shelf electronics, onboard imaging, optical communication, and MEMS-based mechanical steering. The BLISS architecture uses solar radiation pressure as its primary propulsion source and relies on controlled displacement of sail-support tethers to modify the relative geometry between the sail and spacecraft body. Earth-escape and interplanetary trajectory studies show that a BLISS-class spacecraft can, in principle, spiral out from near-Earth orbit, perform heliocentric transfers, and rendezvous with near-Earth objects such as Bennu on mission timescales relevant to small-body exploration. This dissertation further develops the MEMS actuation and microrobotic systems needed to support that spacecraft-level architecture. The MEMS Actuators for control of Solar-sail Tethers (MAST) are presented as the steering and tether-control mechanism for BLISS. MAST devices use MEMS inchworm motors and gap-closing actuators to displace carbon-fiber tether elements, thereby enabling control of sail attitude through center-of-pressure and center-of-mass offset. The Self-righting Quadrupedal Inchworm Driven Spacewalker (SQuIDS) is developed as a candidate microrobotic rover payload that a BLISS-class spacecraft could carry for on-asteroid or small-body surface exploration. SQuIDS addresses the need for local mobility, surface interaction, and self-righting in low-gravity environments where landing orientation and ground contact are uncertain. The actuator-level foundation for future versions of these systems is provided by the Transmission Gap Closing Actuator (TGCA) and $\mu\Delta$ motor work. TGCA-based motors are designed to extend conventional MEMS inchworm actuation by introducing bidirectional, transmission-capable, and variable-output behavior. In the long term, this actuator architecture is intended to replace the more conventional inchworm motors used throughout BLISS, MAST, and SQuIDS, creating a common MEMS motor platform for sail steering, tether control, rover locomotion, and small-body interaction. Taken together, this dissertation presents a linked research program rather than a single isolated device. BLISS defines the spacecraft and mission architecture, MAST provides the solar-sail steering mechanism, SQuIDS extends the mission concept to surface exploration, and TGCA provides a future motor technology for unifying actuation across the platform. The work remains intentionally foundational: several subsystems require additional fabrication refinement, environmental testing, closed-loop control, and integrated validation before flight use. Nevertheless, the designs, models, simulations, fabrication processes, and experimental results presented here establish a coherent path toward MEMS-controlled femtoscale spacecraft and microrobotic explorers for distributed interplanetary science.