Passive-Safety Constrained Free-Flyer Path-Planning with LaplacePotential Guidance at the International Space Station. Departmental Report 9914

A path-planning tool is presented to generate safe trajectories from an initial docking release to a specified observation point and back to docking for a small free-flying robot camera around the International Space Station (ISS). The tool makes use of Ellipse of Safety (EOS) trajectories to enforce long term passive safe requirements in the presence of differential air drag, during the fly around phases of the manoeuvre while transferring between the docking port and observation point. Short-term passive safety (2-3 orbits) is also maintained during all station-keeping and approach manoeuvres by checking the safety of the observation point at the initial planning stage, and through the of use pre-calculated velocities profiles along the rbar for forced motion approaches to the observation point and docking. The observation phase of the mission is enhanced through the use of artificial Laplace potential functions within a constrained volume, to allow for limited manoeuvring close to the observation point enabling the available view to be translated and rotated.