Cygnus Primary Structure Static Load Test Completion
Applied Aerospace Structures Corporation (AASC) successfully completed static load testing on the Cygnus Primary Structure for Orbital. The test program applied loads to the structure to simulate the forces that it will experience during an Antares launch while carrying a fully loaded Pressurized Cargo Module on top. For the load case that simulated the maximum axial acceleration of the rocket, almost 90,000 lb were applied to the cargo module interface ring, which is equivalent to supporting a dry Boeing 737 on top of the structure. Other load cases applied about 35,000 lb to the sides of the structure. The structure performed well during the test and is now at Orbital for integration and test.
The twelve-sided, 103” diameter x 50" tall structure is based on Orbital’s STAR 2 platform design, and is comprised of a forward and aft aluminum ring and graphite facesheets with aluminum honeycomb core for the forward/aft decks, bulkhead, and gussets. The remaining parts of the structure are metal-bonded aluminum facesheet panels.
The composite structure will assist Orbital in delivering cargo payloads to the International Space Station (ISS) under the NASA Commercial Orbital Transportation Services (COTS) demonstration agreement and Commercial Resupply Services (CRS) contract. The structure houses the motors and maneuvering control system for the spacecraft. During launch, the structure will attach to the launch vehicle interface, the Antares launch vehicle payload adaptor, a part for which AASC is currently under contract through another division of Orbital. Cargo will be ferried to the ISS inside a pressurized canister that attaches to the structure made by AASC.