Alternative Grounding Method for MLI Blankets
In the frame of an ESA study RUAG Space has developed a novel grounding method for Multilayer Insulation (MLI) blankets and their connection to satellite structure. Grounding of metallized layers of MLI blankets is of key importance to avoid electrical charging of the blankets. Thus each metallized layer needs to be grounded to a grounding point (GP) on satellite structure. In common practice this is done by using metallic washers in contact with metallized blanket layers and a grounding rivet, being part of a blanket GP. State of the art technology is to connect the rivet to structure ground using wires, which makes integration, de-integration and documentation time consuming tasks - e.g. removing and putting back a blanket requires disconnecting and reconnecting wires. The newly developed grounding method is based on existing technology using on blanket side washers and an adapted rivet but eliminates the need of wires. The blanket is simply grounded by putting it into its final position – no mating or demating of grounding wires is needed. Once the blanket is integrated, grounding is secured by a dedicated grounding stud which is part of the attachment provisions. The grounding stud itself is electrically connected to spacecraft chassis by selected methods, pending on project requirements. It remains on the spacecraft while the blanket can be handled detached from the satellite. Without grounding wires, blankets can be easily removed or put onto the spacecraft while grounding is secured at any time by application of attachment clipwashers. This provides high flexibility and reduced assembly, integration and documentation effort during the spacecraft on-ground operations as well as mass reduction of grounding parts. Qualification for flight (TRL6) was achieved by tests to thermal vacuum cycles and mechanical launch loads. The influence on electromagnetic shielding and DC magnetic properties was investigated by measurements.
RUAG Space GmbH
ICES104: Advances in Thermal Control Technology
W. Gabryel, RUAG Space GmbH, Austria
W. Hoidn, RUAG Space GmbH, Austria
J. Wolf, ESA - European Space Agency, The Netherlands
The 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.