A Brief History
On October 24, 1957, the US Air Force combined the proposals of three companies to develop a rocket powered spaceplane that was to perform multiple military roles, including bombing, reconnaissance, and research. Plans included a timeline of planning until 1963, first flights conducted as glide tests with powered test flights to follow in 1964. The plan was for an unmanned glide missile to be fielded in 1968 and a fully operational manned system by 1974.
Intended to be sent into space atop a rocket and return to Earth on a glide and land like an airplane, the X-20 proposal was quite similar to what became the Space Shuttle (first flight 1981), although the intended use was very different. The X-20 was also meant to be capable of orbital flight, allowing it to stay in space for extended periods, meaning it could bomb or observe anywhere on Earth over a flexible time frame. The first model was to be the X-20 Dyna-Soar I (love those word games!) used for research, the second iteration was to be the X-20 Dyna-Soar II used in the reconnaissance role, and the final version was to be the X-20 Dyna-Soar III used as a strategic bomber.
The 1967 Outer Space Treaty joined by the United States made basing weapons of mass destruction in space or on the Moon illegal, thus negating half of the purpose of the proposed X-20.
In April of 1960, a pool of 7 astronauts was secretly created to provide pilots for the X-20 program, with Neil Armstrong (in 1969 the first man to walk on the Moon) among them. In 1962 the revised list of X-20 pilots and the program itself was unveiled to the public. Flight tests of some of the X-20 instruments were conducted using an NF-101B Voodoo modified fighter plane, and a B-52 bomber was modified to act as a test lift and drop carrier for initial glide tests of the X-20. When the project was cancelled in December of 1963, the modified B-52 became available for other research heavy lift missions.
The reasons for the cancellation of the X-20 Dyna-Soar program centered on the lack of any firm ideas about the employment of the system and the lack of reliable lifting rockets to reliably carry such a heavy (5 tons) payload into space. The early lifting rockets of the Mercury and Gemini program were required to lift far lighter payloads than that needed to launch an X-20.
The design of the proposed X-20 was a delta winged craft a bit similar to the Space Shuttle, but with 2 vertical stabilizers instead of the single, centrally mounted vertical stabilizer found on the Space Shuttle. A bit over 35 feet long and almost 23 feet wide, the X-20 weighed 11,387 pounds when loaded. A self-contained rocket motor with 72,000 foot pounds of thrust was to be installed on the X-20. Maximum designed speed was to be 17,000 mph, with a maximum altitude of over 500,000 feet. The crew was limited to only 1 pilot.
Although never built, the research that went into the X-20 program was valuable toward the development of the Space Shuttle project and influences other follow-on space plane programs being developed today. A few cultural references to the X-20 or a spaceplane similar to the X-20 have appeared in stories and television (The Twilight Zone) as well as the 1969 space movie, Marooned.
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For more information, please see…
Godwin, Robert, ed. Dyna-Soar: Hypersonic Strategic Weapons System: Apogee Books Space Series 35. Collector’s Guide Publishing, Inc., 2003.
The featured image in this article, a photograph of an X-20 Dyna Soar mock-up, is in the public domain in the United States because it is a work prepared by an officer or employee of the United States Government as part of that person’s official duties under the terms of Title 17, Chapter 1, Section 105 of the US Code.