DOW-UAP-D124: Space Access: Where We've Been and Where We Could Go - Hypersonic Gliders, Air-Breathing Rockets and a "Railroad to Space"

Source file: DOW-UAP-D124_AAWSAP-DIRD-Space Access-Where-Weve-Been-and-Where-We-Could-Go-March-8-2010.pdf Originating agency: Defense Intelligence Agency (DIA), Defense Warning Office, under the AAWSAP program Document type: Defense Intelligence Reference Document (DIRD), "Acquisition Threat Support" series; control number DIA-08-1001-006 Date: 8 March 2010 (information cutoff date, ICOD: 1 December 2009) Classification: UNCLASSIFIED//FOR OFFICIAL USE ONLY (the FOUO marking is struck through on every page; released to the public in 2026) Page count: 56 VIRIN: 260918-D-D0360-1113 PURSUE Release: 6

Summary

"Space Access: Where We've Been ... and Where We Could Go" is one of the longer DIRDs in the series: 49 numbered pages plus front matter, 46 figures, 2 tables and four appendices. It was prepared by the Acquisition Support Division (DWO-3) of DIA's Defense Warning Office, and the author's name is redacted as AAP Person 67.

Unlike most papers in the series, this one is to a large extent a professional memoir. The author uses the third person for self-reference ("the author") and recounts that in October 1958 the author's job in the vertical wind tunnel at Wright-Patterson Air Force Base switched to hypersonic flows, and that the author visited Baikonur in 1988, spoke personally with the Soviet glider designer Gleb Lozino-Lozinski, and owns an original model of a 1960s vehicle and two "Qu tubes." The sources are a mix of industry reports from 1964 to 1970, personal conversations and professional literature.

The central claim is stated in the introduction: developing commercial access to space is "a straightforward effort dominated by propulsion and reliability," and "it is not necessarily a matter of technology." In the author's view, the United States already knew in the 1960s how to build a regular round-trip system, but chose expendable rockets derived from ballistic missiles and abandoned the aircraft path. The paper does not mention UFOs or unidentified phenomena.

Research Article

The document, the author and their vantage point

The cover carries the date 8 March 2010, the information cutoff date of 1 December 2009 and the control number DIA-08-1001-006 (page 1). The administrative note on page 2 uses wording familiar from other papers in the series: the paper is "one in a series of advanced technology reports produced in FY 2009" under the AAWSA Program, and questions are to be addressed to AAP Person 1, the program manager, at DIA in Washington.

The structure: introduction (pages 5 to 7); Propulsion Perspective, Hypersonic Configuration Concepts, Thermodynamics and Materials, The Qu Tube, Rocket Propulsion, Up-and-Down Operations, Launch Options, Atmospheric Variations and Conclusion (pages 8 to 49); then four appendices: Historical Perspective, Aeropropulsion Integrated Vehicle, TAV (transatmospheric vehicle) Operational Costs and Landing Ellipses (pages 50 to 55).

Of the 12 technical areas defined in the program's Statement of Objectives (DOW-UAP-D110), the paper mainly addresses configuration and structure, propulsion, materials and lift, through the lift-to-drag ratio of gliders. Appendix C also touches armament, describing "kinetic penetrators" carried in a rocket-accelerated entry nose cone. The word "unidentified" appears only once: a 1960s vehicle model that "showed up on the desk of a now-Boeing employee" and could not be identified, which the author found matched an original model in the author's possession (page 32). There is no connection to unidentified aerial phenomena.

The thesis: "not a technology issue, a hardware issue"

The introduction sets out the thesis sharply. Asked about space access, a group of Aerospace Corporation veterans replied: "It was not a technology issue; it was a hardware issue" (page 6). The author cites the analogy drawn by Dr. D. Bruce Merrifield, Assistant Secretary of Commerce, between preparing technology for manufacture and baseball's minor-league farm system, and notes that Saturn I and Saturn V were readied for a moon flight quickly because they were built on a "frozen design" and existing hardware.

From this follows the historical critique: in the late 1950s a "predisposition," forced by the competition with the Soviet Union, favored rockets derived from ballistic missiles; with Sputnik the aircraft path to space ended with the X-15 and was replaced by the strategy of "loudly blasting to space" with expendable rockets (page 7). According to the author, apart from the experimental Delta Clipper of William Gaubatz and Pete Conrad, no operational launcher has ever successfully aborted, and "a reusable launcher is simply an expendable with some parts reused a few times." This is exactly the assertiveness the official summary qualifies: a characterization of past choices "more assertive than a fully neutral account."

The hypersonic glider: FDL-7 and Model 176

The core of the paper is a defense of one engineering school: the lifting-body hypersonic gliders of the Air Force Flight Dynamics Laboratory (AFFDL) and McDonnell Douglas. Table 1 lists ten configurations from 1958 to 1968, from the FDL-24B to a Russian-inspired "Star Body" (page 13). The decisive difference, the paper says, is the hypersonic lift-to-drag ratio (L/D): a glider with L/D above 2.7 can glide more than 4,500 nautical miles cross range and land in the continental United States from any point in its orbit, without waiting. The Apollo capsule, by comparison, had to wait up to 14 orbits, or 21 hours (page 17).

The author takes on the claim that a lifting body is much heavier than a ballistic capsule. A 1960s government correlation found that a high-L/D glider might weigh almost twice as much as a capsule with the same payload; McDonnell Douglas engineers split the data into three configuration "families" and found weight ratios of only 1.9, 1.7 and 1.4, depending on shape (Equation 3, pages 15 to 16). The "spatular" nose developed by AFFDL together with McDonnell Douglas reduced nose wave drag by 35 to 40 percent.

Page 21 carries a striking anecdote. Lozino-Lozinski limited his BOR gliders to an L/D of 1.7 to 1.8, and the author explains this with two reasons: the Soviet Union was twice as long as the continental United States, and "in personal conversations" Lozino-Lozinski told the author a Russian government agency forced him to limit the glide range to prevent escape to the United States, and that ground control even disabled the deorbit system when the vehicle was within range of the U.S. This is hearsay with no written source. The practical application the author proposes: gliders attached to the space station as lifeboats, letting a crew reach the ground "in less than 90 minutes" in an emergency, compared with a 6-orbit wait for a shuttle-class glider at the station's inclination.

Materials and heat: metal shingles, heat pipes and the Qu tube

The paper describes the Model 176 structure: titanium walls made by diffusion bonding and super-plastic forming, serving as both primary structure and propellant tank wall, covered by radiating metal "shingles." With 1960 materials about 95 percent of aerodynamic heating was radiated back to space and only about 2.5 percent entered the structure; with the attachment methods of the X-33 program, the author says, only 0.5 to 1 percent would enter today (page 27). A porous nickel nose tip that "sweats" water was flight-tested on a BGRV flight in 1966, and a leading edge made of sodium-filled heat pipes was built at McDonnell Douglas and "never failed" (pages 28 to 29). The author recounts seeing a SiC/SiC combustor run at 3,000 degrees Fahrenheit for days at Bordeaux, and regrets that the plant closed.

The most unusual section is "The Qu Tube" (pages 30 to 31): a heat pipe of Chinese origin that, according to a University of Alabama in Huntsville annual report, conducts heat at least 30,000 times better than copper. The author claims the Chinese team "was not about to let this discovery into American hands," and reports owning two smaller tubes. Notably, the excerpt reproduced from the report itself opens with the words "the Qu Tube, or Supertube, is somewhat controversial," and the DIRD offers no independent verification of the claims.

Propulsion, takeoff and launch

In the propulsion section (pages 32 to 36) the author praises Pratt & Whitney's XLR-129 rocket engine, with a turbopump exit pressure of 3,500 psi, which reached full pressure "in just over 3 months," against three years for the space shuttle main engine. According to the text the engine completed 42 simulated flights without overhaul (the caption of Figure 28 says 40 test cycles), and the author quotes Dick Mulready's book claiming NASA canceled the liquid-oxygen turbopump because funding it "would be unfair to our competitors." Russia's RD-0120 engine for the Energia launcher ran 80 simulated flights.

The preferred alternative is an air-breathing rocket up to Mach 5.5: the LACE cycle, in which liquid hydrogen cools and liquefies incoming air, a "deeply cooled" cycle, and the KLIN cycle of V. V. Balepin. According to Figure 2, for a Delta Clipper-type vehicle with a 5.35-ton payload, LACE cuts takeoff gross weight from 334 to 101 tons. The author describes a Russian-British concept for launching a glider from atop an An-225 aircraft: according to Figure 31, LACE removes 150 tons from liftoff weight and allows a payload of more than 11 tons, against 5.45 tons with a conventional rocket (pages 35 to 36).

The takeoff-and-landing section (pages 37 to 40) explains why studies that imposed horizontal takeoff a priori reached the wrong conclusions. An air-breathing rocket with a mass ratio of 5.0 would weigh about 230 tons for vertical takeoff, less than half the 480 tons of an all-rocket; force horizontal takeoff and its weight jumps to about 800 tons. The conclusion: above a weight ratio of 4.3, vertical takeoff or air launch is better. "And so," the author writes, "the rocket proponents have defeated an air-breathing solution since the first aerospace plane in 1958." The launch section describes a vertical launch complex whose "toss-back" boosters rotate 180 degrees and return for a vertical landing, a concept of Joe Thurgau of McDonnell Douglas, and the Baikonur routine: a Soyuz that arrived by train at 0500 hours launched at 1715 hours the same day (pages 9, 35 and 41).

A "railroad to space": the conclusion and appendices

The conclusion (pages 44 to 49) asks: "Forty years after Apollo, why have we advanced so little?" The author compares trips to low orbit to the pioneers' Conestoga wagons, which did not return east, and proposes treating space infrastructure as "a train marshalling and switching yard": orbital stations where vehicles are assembled, refueled and repaired. Figure 44 and Table 2 list 25 elements, from a sustained-use launcher and an orbital fuel station to an orbital clean-up vehicle, a space hotel, a lunar spaceport and planetary exploration vehicles. Along the way the author remarks that "singular reliance" on solar cells may doom space power stations, and relays a personal account that the hub of the MIR station began to leak after 15 years in space.

The appendices add quantitative detail. Appendix A summarizes 1964-65 McDonnell reports on a rotating space station for 21 crew that needed 448 metric tons of supplies a year and at least 74 flights a year, meaning a fleet of ten vehicles. Appendix B compares a vertical-launch rocket with a 7,000-kg payload, weighing 450,000 to 500,000 kg, with an air-breathing vehicle weighing 200,000 to 225,000 kg. Appendix C gives a 1984 cost estimate for a squadron of 14 transatmospheric vehicles: $97 million a year for atmospheric cruise and $251 million for orbital operations, against $71 million for a B-52 squadron and $140 million for refueled B-52s. Appendix D shows the Model 176 could glide a distance equal to the Earth's equatorial circumference.

Significance

The paper deals with no foreign threat and analyzes no hostile technology; it is a historical and polemical essay by an engineer of the X-20 and MOL generation, included in the AAWSAP reference library. Its value to the archive is twofold. First, it documents in great detail, with data from industry reports that are not easily accessible, an American line of development in hypersonic gliders and air-breathing rockets that was abandoned in the 1960s. Second, it illustrates the program's range of topics: alongside papers on antimatter, such as DOW-UAP-D123, and nuclear propulsion, such as DOW-UAP-D126, stands a paper whose purpose is to show that the problem lies not in physics but in engineering persistence.

It should be read with caution. Some claims rest on private conversations with no documentation, some are one-sided toward NASA and the "rocket proponents," and there are small inconsistencies: 42 versus 40 cycles for the XLR-129, and a threshold of "less than four" in the caption of Figure 34 versus 4.3 in the text. One piece of general context is also worth keeping in mind: the paper was written in 2010, before any orbital rocket booster had ever made a powered landing. In December 2015 the first stage of a commercial orbital rocket landed near its launch site for the first time, and since then the idea of a booster that returns to its starting point, which the paper credits to a McDonnell Douglas design, has become operational reality, although by a different route than the gliders the author advocates.

Key People

Locations

Key Concepts

Notable Quotes

"The key requirement is to develop a robust and not necessarily a low-cost infrastructure, without which commercial exploitation of LEO and the moon will not be possible." -- page 5

"It was not a technology issue; it was a hardware issue." -- page 6

"With the X-15's demise, all efforts to fly aircraft to space ended, replaced by the more familiar (but less practical) strategy of loudly blasting to space with expendable rockets derived from undertested ballistic missile hardware, as documented in early failures." -- page 7

"Second, in personal conversations with the author, Lozino-Lozinski indicated a Russian government agency forced him to limit the glide range to ensure recovery in continental Russia and prevent escape to the United States." -- page 21

"And so the rocket proponents have defeated an air-breathing solution since the first aerospace plane in 1958." -- page 40

"But where is our space infrastructure? Forty years after Apollo, why have we advanced so little (as illustrated in Figure 43)?" -- page 45

"The space business has it backwards: There is no commerce until the infrastructure is in place, not vice versa." -- page 46

"Is it a technology issue? Hardly! We have known for 50 years how to create it." -- page 46