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This Defense Intelligence Reference Document, DIA-08-0912-008, is dated 12 January 2010. It was prepared by the Defense Warning Office's Acquisition Support Division at the Defense Intelligence Agency as one of a series of FY 2009 technology reports under the Advanced Aerospace Weapon System Applications program. It reviews materials for launch vehicles, space vehicles and reusable rocket engines, including aluminum alloys, polymer and metal matrix composites, titanium and nickel alloys, and titanium aluminides. It concludes that newer materials and integrated design could improve on the space shuttle.
From the source: Release of 2026-09-18 Incident: 1/12/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys the structural materials needed for advanced aerospace platforms and argues that material choice cannot be separated from overall vehicle design, because launch vehicles, space vehicles, reusable systems, and propulsion hardware each face different temperature, durability, weight, and manufacturing constraints. The report reviews a range of candidate material classes, including advanced aluminum alloys; polymer-, aluminum-, and titanium-matrix composites; titanium alloys; nickel-base alloys; refractory metals; ceramic-matrix composites; carbon-carbon composites; and titanium aluminides. It emphasizes that balancing performance against practical limits such as fabrication methods, cost, inspection, contamination control, and service environment remains a major challenge. Its overall conclusion is that many promising materials exist, but their usefulness depends on application-specific tradeoffs and on closer integration of material selection with design and manufacturing, with some systems judged to be more valuable targets for development than others.
UNCLASSIFIED/ /FOR 8FFI@IAL l:l!H! 8HL'I REUSABLE CREW MODULES The concept of manned orbital crew modules has evolved from the Mercury capsules to the Gemini and Apollo programs to the space shuttle, the first fully reusable crew module. The shuttle also has a combined payload bay used for transporting satellites into orbit and hardware for developing the International Space Station and for repairing and refurbishing the Hubble telescope, among other uses. The reusable nature of the shuttle crew module introduced a number of design and materials selection challenges . Perhaps foremost among these is the requirement for a thermal protection system (TPS) that would protect the crew during reentry and also minimize the intermission refurbishment requirements of the spacecraft itself. During the early days of the shuttle development program, there was much initial interest in a metallic TPS because it appeared to better meet the program's needs. Ultimately, however, ceramic tiles were used on the underbody and carbon-carbon composites (C-CCs) were used on the leading edges of the wings. The shuttle design itself can therefore be characterized as a "cold structure" with an insulating TPS. For example, much of the shuttle load-bearing structure is made of the Al alloy 2219, in part because it is fusion weldable and in part because it retains its strength at moderately elevated temperatures better than other high -strength Al alloys can. The refurbishment needs of the ceramic shuttle tiles after each flight reputedly are considerable and increase with vehicle age. The C-CC wing leading edges are basically not repairable but require scrutiny. Hindsight shows that C CCs "age" and lose much of their fracture toughness during repeated thermal exposure . (This loss of toughness was a prime factor in the Columbia disaster. Had a metallic heat shield that included the wing leading edges been used, this disaster arguably could have been avoided.) If the discussion of a metallic TPS were held today, the outcome might not be much different. Certainly any serious consideration of a reusable single stage-to-orbit vehicle today would need to reopen the discussion of a metallic TPS. The challenges and opportunities associated with a metallic TPS are discussed later. The design efficiency of an integrated TPS and load-bearing structure is extremely attractive. Such a design requires availability of high-temperature alloys that also have good strength at the moderate temperatures to withstand t he aerodynamic and vibrational loads encountered during launch and orbital insertion. Any attractive alloy also must have reasonable intrinsic resistance to oxidation at the reentry temperatures and should be capable of being fabricated into sheet gauges at reasonable cost. Meeting these various requirements in combination becomes quite daunting. Earlier programs such as the DynaSoar reusable ree ntry glider devoted considerable time and resources to examining the use of refractory alloys such as Mo-0.5%Ti (Moly half Ti) and several Columb ia-based alloys for the TPS and some hot structure. All the refractory metal alloys are solid solution strengthened and, consequently, have relatively low ambient temperature strengths. They also are quite dense, making the density-corrected strength even less attractive. Refractory metals and their alloys react extensively when exposed to air at elevated temperatures. Therefore, even if the mechanical property limitations could be overcome, any hot structure would require an oxidation-resistant protective coating. In the case of the DynaSoar program, scientists extensively investigated a surface conversion coating of MoSi2 formed by reacting the Moly half-Ti alloy with Si powder in a high-temperature fluidized bed. With the benefit of hindsight, it is now unclear how a large structure could have been successfully coated in this manner. This is particularly true when the brittle nature of MoSii is 9 UNCLASSIFIED/ 6FOA. OFFICI0L Pili 011! X •
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Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 27 pages are in the text index: search them above, or from the library's search.