Safe Picosatellite Release from a Small Satellite Carrier

Abstract

The Berlin Infrared Optical System satellite, which is scheduled for launch in 2016, will carry onboard a picosatellite and release it through a spring mechanism. After separation, it will perform proximity maneuvers in formation with the picosatellite solely based on optical navigation. Therefore, it is necessary to keep the distance of the two spacecraft within certain boundaries. This is especially challenging because the employed standard spring mechanism is designed to impart a separation velocity to the picosatellite. A maneuver strategy is developed in the framework of relative orbital elements. The goal is to prevent loss of formation while mitigating collision risk. The main design driver is the performance uncertainty of the release mechanism. The analyzed strategy consists of two maneuvers: the separation itself, and a drift-reduction maneuver of the Berlin Infrared Optical System satellite after 1.5 revolutions. The selected maneuver parameters are validated in a Monte Carlo simulation. It is demonstrated that both the risk of formation evaporation (separation of more than 50 km) as well as the eventuality of a residual drift toward the carrier are below 0.1%. In the latter case, formation safety is guaranteed by a passive safety achieved through a proper relative eccentricity/inclination vector separation.