Bonding and Analysis of Composite TRAC Booms for NASA Science Missions

A new deployable spacecraft boom technology called the Triangular Rollable And Collapsible Boom (TRACTM Boom), invented by the Air Force Research Laboratory and exclusively licensed by Roccor, is being considered by NASA for numerous missions including the Comet Rendezvous, Sample Acquisition, Isolation, and Return (CORSAIR) mission being developed by NASA Goddard. For CORSAIR, NASA has baselined a rather robust high strain composite (HSC) TRAC Boom to tether a comet Sample Acquisition and Retrieving Projectile (SARP) to the spacecraft and prevent the harpoon-like penetrator from recoiling back and impacting the spacecraft during retrieval. However, questions remain as to how to design and build a composite TRAC Boom with sufficient strength so as to tolerate the relatively long storage time (several years in-transit to the comet) and relatively high deployment speeds (~30-150 f/s) necessary for the CORSAIR harpoon system. To address this challenge during Phase II, Roccor proposes to improve the performance of the bondline in composite TRAC Booms by reinforcing the adhesive joint and developing mechanical end fittings that allow higher packaging strains while minimizing creep. We also propose to validate a relatively low cost, out-of-autoclave process for affecting the bond, and validate analytical models to simulate the time- and temperature-dependent viscoelastic behavior of composite TRAC bonded joint, and guide engineering qualification of the joints for future NASA missions, including CORSAIR. Moreover, Roccor will also further optimize the system design, including proximal and distall end fittings that connect TRAC Boom into the CORSAIR storage canister and sample return projectile to validate strength and creep performance to mission requirements, and to incorporate load-limiting features that prevent catastrophic failure of the TRAC boom during operation.