Light carbon-fiber structure protects heavy space cargo Published Feb. 23, 2007 By Michael P. Kleiman Space Vehicles Directorate Public Affairs KIRTLAND AIR FORCE BASE, N.M. -- The inaugural performance of a structural configuration and corresponding method for fabricating launch vehicle fairings met the expectations of Space Vehicles Directorate scientists here. The Advanced Grid-Stiffened composite payload fairing was employed during the December 2006 launch of the TacSat-2 micro satellite. Advanced Grid-Stiffened, or AGS, composite payload fairing consists of carbon fibers and epoxy forming beams and an outer skin. The structure is 20 feet long and 5 feet wide. It features a compound-based, triangular rib pattern with an outer covering that resembles a blimp-shaped design. It maintains a strength that is, pound per pound, stronger than steel. The significance is a potential drastic reduction in the cost of composite payload shrouds. Satellites are carried into space by launch vehicles. The payload is fastened at the top of the rocket under the payload fairing, which shelters the satellites before and during the start and on their flight through the atmosphere from thermal, aerodynamic and acoustic effects. In addition, the payload fairing provides the launcher with an aerodynamically optimised shape. The payload fairing is jettisoned once the launch vehicle has left the atmosphere. "The AGS Composite Payload Fairing serves as a more efficient way to use the strongest materials to work with, as it makes the most use of carbon fiber composites in their strong direction," said Dr. John Higgins. He is the AGS composite payload fairing program manager with the Space Vehicles Directorate, one of nine technical directorates under the Air Force Research Laboratory. "This technology allows us to build stronger, lighter, low-cost structures, which can carry more payloads to orbit. "The AGS Composite Payload Fairing project has been the best example of a team effort between industry and government-related organizations," Dr. Higgins continued. "In addition, the program has used about all the technical competence and expertise the Space Vehicles Directorate has to offer to develop this innovative product. The whole thing had to be integrated efficiently, and we worked with the two contractors (Boeing Phantom Works and Orbital Sciences Corp.) to ensure that they were satisfied with the grid-stiffened structure's performance and safety design." Boeing Phantom Works constructed the initial two composite fairings. The Space Vehicles Directorate then conducted qualification testing on one of the structures. During the evaluations, the advanced grid-stiffened arrangement successfully held up to 125 percent of the load it would experience in service. To compliment the existing product, the Kirtland-based team created an acoustic blanket system to reduce the potentially damaging effects of noise (from launch) on the payload. Orbital Sciences Corp., conducted additional assessments to ensure the hardened carbon-fiber assembly could withstand the pressure exerted on it by blast separation from their Minotaur I rocket. One of the two fairings, shipped back and forth across the country for various appraisals, ended up protecting the TacSat-2 micro satellite. "We are currently trying to introduce the carbon compound fairing with other systems, such as the Evolved Expendable Launch Vehicle," said Dr. Higgins.