To validate the principle of robot walking and manipulation in the future space tasks, a 7-DOF space robotic arm (SRA), its end effecter (EE) and grapple fixture (GF) were built. Also, a ground simulator was set up to provide a microgravity condition for the robot space grasping and walking tasks. We presented a Cartesian impedance control method for the SRA based on the feedback of a 6D force/torque sensor on the EE. Experiments proved the effectiveness and safety of the space walking robot and its ground simulator.