by Dr. Kevin Kendig, AFRL Accomplishment: Working with commercial industry, scientists at the Air Force Research Laboratory (AFRL) developed, tested, and transitioned beryllium-aluminum (Be-Al) alloys to make components for Air Force and NASA spacecraft launched in early 2005. Four components are on the Air Force’s XSS-11 experimental polar-orbiting satellite, which is designed to fly around and inspect other U.S. orbital objects such as spent boosters and dead satellites. A fifth component is being used on one of three miniature spacecraft (micro-sats) deployed by NASA under the Space Technology 5 (ST5) program, which is designed to test innovative concepts and technologies in the harsh environment of space. The alloys were created under the Metals Affordability Initiative (MAI) overseen by the Materials and Manufacturing Directorate’s (ML) Metals, Ceramics and Nondestructive Evaluation (NDE) Division. Additional applications have been identified. Payoff: Beryllium-aluminum research has increased the technology base for space vehicle design and development using cost-effective manufacturing capabilities derived from highly detailed, collaborative design processes. Be-Al alloys are stronger than materials normally used to build spacecraft components and, because they weigh less than conventional materials, have lowered the cost of placing spacecraft into orbit. Background: Be-Al alloys have been used successfully in many high performance applications such as gas turbine engines, racing cars, space launch vehicles, and satellite structures due to their unique combination of low density (~0.08 lb/in 3) and high stiffness (~30x10 6 psi). Be-Al’s specific strength (strength divided by density) and stiffness characteristics surpass those of conventional titanium alloys, resulting in reduced structural weight and increased payload and/or performance. Be-Al is a possible replacement for pure beryllium since it has greater stiffness than aluminum alloys at much lower material cost than beryllium and improved formability. Be-Al qualities facilitate near-net shape component fabrications, hence, additional cost reductions.
The successful development of Be-Al components for the XSS-11 (Experimental Small Satellite) and ST5 programs expanded the use of Be-Al in both primary and secondary structural applications. ML’s research and development effort was managed by the Metals, Ceramics and NDE Division, and included scientists and engineers from commercial industry. The R&D team was comprised of equipment manufacturers and material suppliers. The manufacturers had the design and component validation responsibility, and the suppliers had the lead in developing cost-effective manufacturing technologies. Be-Al alloys investigated under the MAI effort covered a beryllium content range of 35 percent to 65 percent by weight, with the focus being on materials with lower beryllium contents to better manage costs. Of significant importance, the researchers were successful in joining subassemblies to produce complex structures. They also made important strides in materials development and component selection and design, as well as Be-Al component fabrication and testing. The ML effort also succeeded in formulating and demonstrating the value of detailed collaborative design processes and the feasibility of making near-net shape and net shape parts. The Air Force’s XSS-11 and NASA’s ST5, comprised of three miniature spacecraft, were both launched from Vandenberg AFB, Calif. XSS-11’s mission is to demonstrate an ability to autonomously plan and rendezvous with approved orbiting objects near the satellite’s orbit. During the 12- to 18-month mission in space, the satellite will rendezvous with six to eight U.S.-owned objects in its orbit, i.e., inactive or dead research satellites or spent rocket stages. Part of NASA’s New Millennium Program, ST5's objective is to demonstrate and flight-qualify several innovative technologies and concepts for application to future space missions. During flight validation of its technologies, ST5 may measure the effect of solar activity on the Earth's magnetosphere, the uppermost atmosphere surrounding the planet.
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