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AAWSAP DIRD, Space Access: Where We’ve Been and Where We Could Go, March 2010

U.S. Department of War · 2010-03-08 · 56 pages · text from the file's own layer

This Defense Intelligence Reference Document, dated 8 March 2010, was prepared by the Defense Intelligence Agency's Defense Warning Office under the Advanced Aerospace Weapon System Applications Program. It is one of a series of advanced technology reports. It surveys the history of space access concepts, covering hypersonic gliders, air-breathing and rocket propulsion, materials, launch options and operating costs. The report argues that reliable, schedulable access to low Earth orbit is mainly a hardware and organizational problem rather than a technology problem.

From the source:Release of 2026-09-18 Incident: 3/8/10, 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 is a historical and conceptual survey of space access systems, contending that the main barrier to routine access to space is a failure to build durable, reliable, operational hardware and the supporting infrastructure needed for regular service to and from low Earth orbit. The report reviews earlier launch and aerospace concepts, especially reusable and aircraft-like approaches, and suggests that U.S. space access development became too strongly centered on expendable rockets derived from ballistic missiles rather than bespoke systems designed for repeated space access and payload delivery. Its central claim is that meaningful future progress will depend on creating a purpose-built space transportation infrastructure, including frequent round-trip capability and orbital support networks, rather than continuing to rely on one-off launch vehicles. Overall, the document presents a forceful case for infrastructure-first space development, though its characterization of past technological choices is more assertive than a fully neutral account of past U.S. space programming.

UNCLASSIFIED/ /EOR OEEICI0L: Pi'li ODIL:¥
On other McDonnell hypersonic configurations with all-movable control surfaces, the
interface between the fin and the body became a critical heating issue for the rotating
shaft attach ing the fin to the body. This was an area of concern on this vehicle, and
specially instrumented fins were installed to measure the local heating. Again, the
thermographic phosphors were used to map the heating. Figure 20 shows the model in
Figure 17 at a maximum 48-degree angle of attack. Fin heating distributions were
made at 16-, 24-, 34-, and 48-degree angles of attack 12 and are shown in Figure 21.
The brighter the phosphor is, the lower its temperature is (the phosphor darkens as the
surface temperature increases). So the area adjacent to the body is at a lower
temperature than on the fin. In fact, examining Figure 21 shows that for all angles of
attack tested, there was always the cool layer adjacent to the body. So the fin
attachment journal/shaft would not be a thermal problem. At angles of attack lower
than 16 degrees, the heating became less intense. This tail configuration of a fixed
anhedral lower fin with trailing edge controls and an all-movable upper fin provided the
control authority over the entire mach range required for stability and control and did
not have a thermodynamic issue with fin attachment heating.
o = 48°
Figure 20. Thermographic Phosphor Image of
Model 176 at Near-Maximum Angle of Attack
FIG. 6. ISODENSITRACER maps for lifting body tail fin for four
angles ot attack; contours show qr.ocw,/qun1u,,m,
Figure 21. From L/D Maximum to Maximum Angle
of Attack, There is Always a Cool Sublayer
Adjacent to the Wall
With 1960 materials and manufacturing methods, about 95 percent of the aerodynamic
heating was radiated to space, about 2.5 percent was retained in the shingles, and
about 2.5 percent was transferred into the titanium tank/primary structure. Using
Goodrich Aerospace's standoff/attachment techniques developed for the X-33, today
around 0.5 to 1 percent of the aerodynamic heating would be transferred into the
titan ium tank/primary structure . The shingle material would also be better today.
Figure 22 shows a silicon carbide matrix re inforced with silicon carbide fibers that was
shown at the 1988 Paris Air Show. A combustor of this material was operated at 3,000
° F continuously for a number of days at SEP's Bordeaux plant, as witnessed by the
author. Unfortunately, SEP was subsequently taken over by another company and
promptly closed. The parts manufacturing at Bordeaux was truly impressive to
someone in space systems but too costly to a subsonic round engine manufacturer.
UNCLASSIFIED/ /FOR. OFFI@IAL YSIE 8HL'/
20

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Official release, from the pursue 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.