Robotics facilities have a long history in the development of space equipment, since they allow to perform tests on systems like guidance, navigation and control, visual-based navigation and docking mechanisms. Those facilities are based on two manipulators, one representing the a target satellite, the other the chaser satellite which perform a relative motion with respect to the first. This approach has been used in the past to perform tests on docking operations, visual-base navigation system to populate databases. Delft University of Technology recently developed its own robotics facility for GNC and multisatellite systems applications. It hosts two robots on a moving base, which work in synergy to extend the operational space. They operate in a dark environment, where there are lights to simulate the sun disturbance and a beamer that projects the Earth to have a representative background. The purpose of this paper is to describe the laboratory, along with the control architecture of the robots and provide some tests executed to assess the accuracy of them in tracking a given trajectory.

This brief presents a comprehensive approach for the modeling of micropropulsion systems based on the vaporization of a liquid. The model combines the analytical and empirical relations derived from extensive experimental analysis and fundamental physical laws. This allows modeling of key parameters, such as mass flow rate, for the entire system comprising a tank to store the liquid propellant, a valve to control the mass flow, and a microthruster that vaporizes the propellant and accelerates it generating thrust. The model is evaluated by a sensitivity analysis considering the boundaries of the modeling space, and it has been tested in a simulation loop demonstrating the attitude control of a nanosatellite using a set of four thrusters. The results of the simulation are used to test the developed model.