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This Defense Intelligence Reference Document, prepared by the Defense Intelligence Agency and dated 8 March 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It gives a historical and technical review of how to reach space and return. It covers hypersonic gliders, air-breathing and rocket propulsion, thermodynamics and materials, and launch options. It argues that reliable, schedulable access to low Earth orbit is mainly a hardware and propulsion problem rather than a technology one.
UNCLASSIFIED/ /Pel\ 8PPll!ltllt '11815 &n•LY tunnel model of the McDonnell Douglas Astronautics Company Model 176 installed in the McDonnell Aircraft Company Hypersonic Impulse Tunnel for a heat transfer mapping test is shown in Figure 17. Note that, conforming to the piloting concepts of the 1960s, it has a clearly distinct windshield. The model accomplished thermal mapping to determine the heat transfer distributions on the body and upper fins. Figure 17. Model 176 in the McDonnell Douglas Hypervelocity Impulse Tunnel (circa 1964) for Thermographic Phosphor Heat Transfer Mapping, Including the Upper Fin. Among the important determinations that resulted from these heat transfer tests was that the sharp-leading-edge, flat-bottomed, trapezoidal cross section reduced the heating to the sides and upper surfaces, as shown in Figure 18. In the range of angles of attack corresponding to maximum hypersonic L/D ratio, the sharp leading-edge corner separates and reduces the upper surface heating. Because of this separation, the isotherms are parallel to the lower surface and are 2,100 to 2,400 °F (1,149 to 1,316 °C) cooler than on the compression surface. The upper control fins are hot, but there are approaches and materials applicable to control surfaces. The temperatures shown are radiation equilibrium temperatures. With nose water transpiration cooling (demonstrated in a flight test in 1966) and heat pipe leading edges (demonstrated at NASA Langley in 1967-68), the temperatures of the nose and leading edges are 212 °F and 1,300 °F (100 °C and 704 °C ), respectively. The thermal mapping enabled identification of primary flow characteristics in the boundary layer of the vehicle. In 18 UNCLASSIFIED/ ,<EiOAt OEiEil&l11J.k laUiEii SU.LY
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 56 pages are in the text index: search them above, or from the library's search.