On-orbit servicing involves a new class of space missions in which a servicer spacecraft is launched into the orbit of a target spacecraft, the client. The servicer navigates to the client with the intention of manipulating it, using a robotic arm. Within this framework, this work presents a new robotic experimental facility which was recently built at the DLR to support the development and experimental validation of such orbital servicing robots. The facility allows reproducing a closeproximity scenario under realistic three-dimensional orbital dynamics conditions. Its salient features are described here, to include a fully actuated macro-micro system with multiple sensing capabilities, and analyses on its performance including the amount of space environment volume that can be simulated.

High-frequency coastal radars (HFRs) have proved to be excellent tools for monitoring coastal circulation, providing synoptic, high spatial and temporal resolution surface current data in real time. They may also give detailed information on the surface wave field of coastal areas. An HFR has been operating in the Gulf of Naples (south-eastern Tyrrhenian Sea) since 2004. In this paper we show the results of their utilisation in the study of the Gulf dynamics and sea state, with a focus on potential applications in the context of operational oceanography.

This paper addresses the coordinated control of the spacecraft's attitude and the end-effector pose of a manipulatorequipped space robot. A controller is proposed to simultaneously regulate the spacecraft's attitude, the global center-ofmass (CoM), and the end-effector pose. The control is based on a triangular actuation decomposition that decouples the endeffector task from the spacecraft's force actuator, increasing fuel efficiency. The strategy is validated in hardware using a robotic motion simulator composed of a seven degrees-of-freedom (DOF) arm mounted on a 6DOF base. The trade-off between control requirements and fuel consumption is discussed.

During the robotic capture of a target object on orbit, accidental contacts may happen. During contacts, momentum is transferred to the system, causing a drift of the space robot in the inertial space. When no remediation is taken, the arm might converge to singularity or workspace limit within seconds, compromising the capture operation. This article presents a method to control the end-effector while simultaneously extracting any accumulated momentum in the system to cancel the drift. A feature of the method is that external actuators are only used for the momentum extraction and not to counterbalance the manipulator control forces. The control is validated with experiments using a Hardware-In-the-Loop (HIL) robotic simulator composed of a 7DOF (Degrees Of Freedom) arm mounted on a 6DOF moving base.