Ejection and recovery system for CubeSat sized ejectables on sounding rockets

Many sounding rocket experiments have the requirement to be free flying due to their size or the required precision of their measurements which would be falsified by other experiments on-board the same sounding rocket. This paper outlines the ejection and recovery system that was flown on the sounding rocket REXUS13 in May 2013 as part of the StrathSat-R experiment. The ejection system consists of two free flying units (whose dimensions are that of a one unit cube satellite) ejected from the side of an experimental module. The cubes are ejected via compressed springs which are constrained during launch by a stainless steel cable that holds the hatches in place. A pyro cutter is then used to sever the steel cable at apogee in order to release the cubes in free space. During descent, a recovery system consisting of a parachute, a GPS receiver, a Globalstar transmitter and a radio beacon is activated and used to locate the two cubes after impact. The parachute is automatically released at ~5km enabling the GPS receiver to locate the falling cubes and transmit their positions over the Globalstar satellite system and the radio beacon to the ground station. This paper will present the mechanical design of the ejection system and the electronic design and component selection of the recovery system.