Adhesion-based space climbing robots, with their flexibility and multi-functional capabilities, are seen as a promising candidate for in-orbit maintenance. However, challenges such as uncertain adhesion establishment, unexpected detachment, and body motion unsteadiness in microgravity environments persist. To address these issues, this paper proposes a coordinated force–position compliance control method that integrates novel adhesion establishment and rotational detachment strategies, integrated into the gait schedule for a space climbing robot. By monitoring the foot-end reaction forces in real time, the proposed method establishes adhesion without risking damaging the spacecraft exterior, and smooth detachment is achieved by rotating the foot joint instead of direct pulling. These strategies are dedicated to reducing unnecessary control actions and, accordingly, the required adhesion forces in all feet, reducing the possibility of unexpected detachment. Climbing experiments have been conducted in a suspension-based gravity compensation system to examine the merits of the proposed method. The experimental results demonstrate that the proposed rotational detaching method decreases the required pulling force by 65.5% compared to direct pulling, thus greatly reducing the disturbance introduced to the robot body and other supporting legs. When stepping on an obstacle, the compliant control method is shown to reduce unnecessarily aggressive control actions and result in a reduction in relevant normal and shear adhesion forces in the supporting legs by 44.8% and 35.1%, respectively, compared to a PID controller.

The rapid proliferation of low Earth orbit (LEO) megaconstellations has made operational resilience during geomagnetic storms an increasingly pressing concern, as even moderate storms can induce severe satellite drag, disrupt intersatellite links, and compromise mission safety. Accurate orbit prediction during geomagnetic storms remains a critical challenge, as storm-induced atmospheric density variations severely degrade the performance of empirical and physical models. This paper proposes a cross-referential orbit propagation method that leverages GNSS telemetry sharing among constellation satellites, without requiring any atmospheric model or explicit space weather inputs. The method consists of two stages: a backward propagation stage that corrects onboard GNSS orbit determination errors by averaging over multiple historical reference arcs, and a forward propagation stage that transfers the actual drag effects from a single reference satellite to the satellite of interest. Surrogate neural network models are constructed to accelerate the workflow replacing traditional numerical integration. Validation using simulated Starlink satellites during the 40 most severe storm days from 1963–2020 shows that the proposed method achieves a 3-hour along-track position error of 32.1 m RMS at 560 km altitude, representing an 84% reduction compared to HPOP without space weather input. Real G60 telemetry data further corroborates the assumed OD error evolution pattern. The method's independence from space weather forecasts and ground uploads makes it particularly suitable for fully onboard autonomous operation in large-scale LEO constellations.

Combat aircraft often require the engine to accelerate as fast as possible in response to the demand of maneuvering. The engine acceleration rate, however, is limited by the compressor surge constraint, which prevents more fuel addition that, otherwise, could provide for higher net shaft torque, and thus, faster acceleration. This paper examines the idea of using the electric starter/generator (ES/G) system to provide additional net shaft torque during this critical phase of acceleration. The idea is examined by simulations using a quasi-one-dimensional dynamic compressor flow model coupled with a lumped combustor–turbine model. A notional single-spool turbojet with a low overall pressure ratio is modeled and simulated. Simulation results suggest that an ES/G, when used as an electric-assist motor during acceleration, can help the engine to accelerate roughly 11, 48, and 70% faster compared to the case without ES/G participation, by using electric power roughly equivalent to 0.1, 1, and 3% of full-speed fuel combustion power, respectively. Furthermore, the respective increase in the acceleration rate leads to an additional 19, 80, and 113% of propulsion impulse, respectively (i.e., thrust integrated over time), during the first 5 s following the acceleration command.