A prototype robot that can explore small asteroids and comets with low gravitational attraction has been designed, built, and tested. The three-armed robot has four-digit hands with compliant, multi-phalanx fingers that grip a rocky surface using an array of microspines. These microspine assemblies are patterned after a design that was first demonstrated on an omni-directional microspine gripper at the Jet Propulsion Laboratory utilizing only single-phalanx digits. The new design expands the ability of the original gripper to conform to irregular surface variations, providing improvements in anchoring performance and creating a dexterous robotic hand. The robot is capable of traversing and maneuvering across an asteroid-like surface in simulated microgravity conditions. The mechanical design of the gripper and robot, the control system, the microgravity testing apparatus used to test the robot, and experimental results are described here. Future iterations of this prototype robot can provide a robust mobility platform for small body exploration and sampling missions.