Deployment Analysis of Lenticular Jointed Antennas Onboard the Mars Express Spacecraft

Extensive analytical and experimental activities were carried out that culminated in successful deployments in May and June of 2005 of three lenticular, jointed booms that formed a first of its kind of ground penetrating radar antenna onboard the Mars Express spacecraft. These activities went well beyond the normal required tasks due to a postlaunch realization that the stowed booms retained at high level of stored energy. This high level of stored energy resulted in an uncontrolled boom deployment rather than predictable boom deployment. Experimentally measured straight section properties and hinge properties were incorporated into specialized modeling techniques that were then used to simulate the boom lenticular joints. System level models were exercised to understand the boom deployment dynamics and spacecraft level implications including spacecraft attitude control and possible entanglement. Discussion includes a comparison of deployment simulation results to measured flight data taken during the three boom deployments. Important parameters that govern lenticular joint behavior are outlined and a short summary of lessons learned and recommendations is included to better understand future applications of this technology.