From: skunk-works-digest-owner@harbor.ecn.purdue.edu To: skunk-works-digest@harbor.ecn.purdue.edu Subject: Skunk Works Digest V4 #36 Reply-To: skunk-works-digest@harbor.ecn.purdue.edu Errors-To: skunk-works-digest-owner@harbor.ecn.purdue.edu Precedence: bulk Skunk Works Digest Thursday, 14 October 1993 Volume 04 : Number 036 In this issue: Science Dawn, Science Realm, Have Region explained F-117 Bay doors See the end of the digest for information on subscribing to the skunk-works or skunk-works-digest mailing lists and on how to retrieve back issues. ---------------------------------------------------------------------- From: THOMSONAL@CPVA.SAIC.COM Date: Wed, 13 Oct 1993 7:09:50 -0700 (PDT) Subject: Science Dawn, Science Realm, Have Region explained Sorting out previously black programs: From Aviation Week and Space Technology, 11 October 1993, p.49 "The last decade's work on SSTO was sparked by a December, 1982, proposal by Boeing to build a winged, sled-launched single-stage orbiter powered by a space shuttle main engine (SSME) for $1.4 billion. This 'subscale' launcher was to take 4,000 lb. to polar orbit. A full-scale version was designed to Strategic Air Command requirements for B-52-style runway operations and would have weighed 1.2 million lb. to orbit 20,000 lb. Sled velocity would have been an impractical 500 fps. "These classified studies were originally code-named Science Dawn in 1983. McDonnell Douglas and Lockheed joined the effort, and the program was renamed Science Realm in 1985-1986. Takeoff weights were 1.2-1.5 million lb. and dry weights were 100,000-150,000 lb. McDonnell Douglas added a down- pointing SSME in the nose to cater for the runway requirements, and Lockheed had a ramped takeoff with two solid boosters. The horizontal takeoff requirement appeared to be warping the design, one official said. 'Rockets have good thrust-to-weight and you might as well use it for vertical takeoff,' he said. "In 1986, as the single-stage effort shifted to the air-breathing National Aerospace Plane (NASP), Science Realm became the Have Region program 'to throw the rocket guys a bone.' Have Region was run secretly out of the NASP office and built prototype structures with 1970s technology to see if it was possible to quickly fly a vehicle. The materials were primarily titanium and high-temperature superalloys. "Each of the three contractors built prototype fuselage cross sections. Two were 40% scale, and the third, built by McDonnell Douglas, was full-scale, weighed 5,000 lb. and cost $15 million to develop and test. About $40 million was spent on Have Region, including about $8 million in contractor funds. With Science Dawn and Science Realm, the overall effort was about $60 million. "The test articles were within 3% of required SSTO design weights, and the need to withstand reentry gave them a more robust skin than on expendable rockets. But there were failures that high-lighted the difficulty of employing these materials for reusable structures containing cryogenic propellant while withstanding reentry heat. "Have Region showed it was possible to make a single-stage orbiter with these materials, an official said. But at the same time, some of the simpler materials studied by NASP -- graphite epoxy for liquid hydrogen fuel tanks, aluminum lithium for liquid oxygen tanks, and various external insulation materials -- were more appealing than Have Region technology. "Have Region was winding down in 1989, and the Strategic Defense Initiative Organization decided to fund a $15 million study to see how the newer technologies could be incorporated in a single-stage rocket. Titanium aluminide and other exotic and expensive NASP materials were not used. These studies by Rockwell, General Dynamics, McDonnell Douglas and Boeing led into the current DC-X program. Because it is only an operational demonstrator, the DC-X uses conventional, low-risk materials. "The newer materials, along with stouter shapes and new structural technologies, result in 40-45% less dry weight and more durability than 1960s rocket practice, an official said..." ------------------------------ From: Rick Pavek Date: Wed, 13 Oct 1993 12:48:35 -0700 Subject: F-117 Bay doors I have a video that clearly shows the bay doors are hinged. The whole drop sequence takes place in less than two seconds... Rick SR-75/XR-7 _|_*O*_|_ | Rick Pavek \ __|__ / | HA!! kuryakin@halcyon.com \_______/_(O)_\_______/ | Ruby - \___/---\___/ | Galactic Gumshoe ------------------------------ End of Skunk Works Digest V4 #36 ******************************** To subscribe to skunk-works-digest, send the command: subscribe skunk-works-digest in the body of a message to "listserv@harbor.ecn.purdue.edu". 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