On an innovative deployment concept for large space structures

Large deployable space structures are mission-criti cal technologies for which deployment failure cannot be an option. The difficulty to full y reproduce and test on ground the deployment of large systems dictates the need for e xtremely reliable architectural concepts. In 2010, ESA promoted a study focused at the pre-development of breakthrough architectural concepts offering superior reliabilit y. The study, which was performed as an initiative of ESA Small Medium Enterprises Office (http://www.esa.int/SME/), by Kayser Italia at its premises in Livorno (Italy), with Uni versita' di Roma TorVergata (Rome, Italy) as sub-contractor and consultancy from KTH (Stockholm, Sweden), led to the identification of an innovative large deployable structure of “ten segrity” type, which achieves the required reliability because it permits a drastic reduction in the number of articulated joints in comparison with non-tensegrity architectures. The i dentified target application was in the field of large antenna reflectors. The project focu sed on the overall architecture of a deployable system and the related design implicatio ns. With a view toward verifying experimentally the performance of the deployable structure, a reduced-scale breadboard model was designed and manufactured. A gravity off-loading system was designed and implemented, so as to check deployment functionality in a 1-g environment. Finally, a test campaign was conducted, to validate the main design assumptions as well as to ensure the concept’s suitability for the selected target appli cation. The test activities demonstrated satisfactory stiffness, deployment repeatability, a nd geometric precision in the fully deployed