Boeing X-20 Dyna-Soar#Operational history

File:Boeing X-20 Dyna-Soar after separation from booster 1961.jpgThe concept underlying the X-20 was developed in Germany during World War II by Eugen Sänger and Irene Bredt as part of the 1941 {{lang|de|Silbervogel}} proposal. This was a design for a rocket-powered bomber able to attack New York City from bases in Germany and then fly on for landing somewhere in the Pacific Ocean held by the Empire of Japan. The idea would be to use the vehicle's wings to generate lift and pull up into a new ballistic trajectory, exiting the atmosphere again and giving the vehicle time to cool off between the skips.{{cite book |last=Duffy |first=James |title=Target: America — Hitler's Plan to Attack the United States |publisher=Praeger |year=2004 |page=[https://archive.org/details/isbn_9780275966843/page/124 124] |isbn=0-275-96684-4 |url-access=registration |url=https://archive.org/details/isbn_9780275966843/page/124 }} After the war, it was demonstrated that the heating load during the skips was much higher than initially calculated and would have melted the spacecraft.{{cite book |last=Reuter |first=Claus |url=https://books.google.com/books?id=Sr6JtOoWghkC |title=The V2 and the German, Russian and American Rocket Program |publisher=German–Canadian Museum of Applied History |date= 2000 |isbn=9781894643054 |page=99}}

Following the war, many German scientists were taken to the United States by the Office of Strategic Services's Operation Paperclip, bringing with them detailed knowledge of the Silbervogel project.Dornberger 1956, pp. 19–37. Among them, Walter Dornberger and Krafft Ehricke moved to Bell Aircraft, where, in 1952, they proposed what was essentially a vertical launch version of {{lang|de|Silbervogel}} known as the "Bomber Missile", or "BoMi".{{cite web |url=http://www.astronautix.com/b/bomi.html |title=Bomi |website=www.astronautix.com |url-status=dead |archive-url=https://web.archive.org/web/20170606114831/http://astronautix.com/b/bomi.html |archive-date=June 6, 2017 |df=mdy-all}}{{cite web |url=http://www.dtic.mil/dtic/tr/fulltext/u2/073754.pdf |title=MX-2276 Advanced Strategic Weapon System Aerodynamics |access-date=2015-02-10 |url-status=dead |archive-url=https://web.archive.org/web/20150210112513/http://www.dtic.mil/dtic/tr/fulltext/u2/073754.pdf |archive-date=February 10, 2015 |df=mdy-all }}

These studies all proposed various rocket-powered vehicles that could travel vast distances by gliding after being boosted to high speed and altitude by a rocket stage.Duffy 2004, p. 124. The rocket booster would place the vehicle onto a suborbital, but exoatmospheric, trajectory, resulting in a brief spaceflight followed by re-entry into the atmosphere. Instead of a full re-entry and landing, the vehicle would use the lift from its wings to redirect its glide angle upward, trading horizontal velocity for vertical velocity. In this way, the vehicle would be "bounced" back into space again. This skip-glide{{cite book |last1=Launius |first1=Roger D. |last2=Jenkins |first2=Dennis R. |title=Coming home : reentry and recovery from space |date=2012 |publisher=National Aeronautics and Space Administration |location=Washington, DC |isbn=978-0160910647 |page=170 |url=https://books.google.com/books?id=7k1sawDR-kEC&pg=PA170}} method would repeat until the speed was low enough that the pilot of the vehicle would need to pick a landing spot and glide the vehicle to a landing. This use of hypersonic atmospheric lift meant that the vehicle could greatly extend its range over a ballistic trajectory using the same rocket booster.

There was enough interest in BoMi that by 1956 it had evolved into three separate programs:

• RoBo (Rocket Bomber), updated version of BoMi.Neufeld 1995, pp. 19, 33, 55.{{cite web |url=http://www.astronautix.com/r/robo.html |title=Robo |website=www.astronautix.com |url-status=dead |archive-url=https://web.archive.org/web/20170606114253/http://astronautix.com/r/robo.html |archive-date=June 6, 2017 |df=mdy-all}}
• Brass Bell, a long-range reconnaissance vehicle.{{cite web |url=http://www.astronautix.com/b/brassbell.html |title=Brass Bell |website=www.astronautix.com |url-status=dead |archive-url=https://web.archive.org/web/20170707061919/http://www.astronautix.com/b/brassbell.html |archive-date=July 7, 2017 |df=mdy-all}}{{cite web |url=http://www.dtic.mil/dtic/tr/fulltext/u2/136057.pdf |title=Brass Bell Reconnaissance Aircraft Weapon System |access-date=2015-02-10 |url-status=dead |archive-url=https://web.archive.org/web/20150210111504/http://www.dtic.mil/dtic/tr/fulltext/u2/136057.pdf |archive-date=February 10, 2015 |df=mdy-all }}
• Hywards (Hypersonic Weapons Research and Development Supporting system), a smaller prototype system to develop the technologies needed for Robo and Brass Bell.{{cite encyclopedia |url=http://www.astronautix.com/h/hywards.html |title=Hywards |encyclopedia=Encyclopedia Astronautica |access-date=2015-02-10 |df=mdy-all |url-status=dead |archive-url=https://web.archive.org/web/20161228084416/http://astronautix.com/h/hywards.html |archive-date=December 28, 2016 }}

File:Dyna-Soar.jpgDays after the launch of Sputnik 1 on 4 October 1957, on either October 10History of the X-20A Dyna-Soar, Clarence J. Geiger, Sep 1963 www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA951933 or October 24,{{Harvard citation no brackets|Godwin|2003|p=38}} the USAF Air Research and Development Command (ARDC) consolidated Hywards, Brass Bell, and Robo studies into the Dyna-Soar project, or Weapons System 464L, with a three-step abbreviated development plan. The proposal drew together the existing boost-glide proposals into a single vehicle designed to carry out all the bombing and reconnaissance tasks examined by the earlier studies, and would act as successor to the X-15 research program.

The three stages of the Dyna-Soar program were to be a research vehicle (Dyna-Soar I), a reconnaissance vehicle (Dyna-Soar II, previously Brass Bell), and a vehicle that added strategic bombing capability (Dyna-Soar III, previously Robo). The first glide tests for Dyna-Soar I were expected to be carried out in 1963, followed by powered flights, reaching Mach 18, the following year. A robotic glide missile was to be deployed in 1968, with the fully operational weapons system (Dyna-Soar III) expected by 1974.{{Harvard citation no brackets|Godwin|2003|p=65}}

In March 1958, nine U.S. aerospace companies tendered for the Dyna-Soar contract. Of these, the field was narrowed to proposals from Bell and Boeing. Even though Bell had the advantage of six years' worth of design studies, the contract for the spaceplane was awarded to Boeing in June 1959 (by which time their original design had changed markedly and now closely resembled what Bell had submitted). In late 1961, the Titan III was chosen as the launch vehicle. The Dyna-Soar was to be launched from Cape Canaveral Air Force Station, Florida.

File:Deepcold dyna final 240.jpg]]

The overall design of the X-20 Dyna-Soar was outlined in March 1960. It had a low-wing delta shape, with winglets for control rather than a more conventional tail. The framework of the craft was to be made from the René 41 super alloy, as were the upper surface panels. The bottom surface was to be made from molybdenum sheets placed over insulated René 41, while the nose-cone was to be made from graphite with zirconia rods.

Due to changing requirements, several versions of the Dyna-Soar were considered, all sharing the same basic shape and layout. A single pilot sat at the front, with an equipment bay situated behind. This bay contained data-collection equipment, weapons, reconnaissance equipment, or a four-person mid-deck in the case of the X-20X shuttle space vehicle. A Martin Marietta Transtage upper stage attached to the aft end of the craft would allow orbital maneuvers and a launch abort capability before being jettisoned before descent into the atmosphere. While falling through the atmosphere an opaque heat shield made from a refractory metal would protect the window at the front of the craft. This heat shield would then be jettisoned after aerobraking so the pilot could see, and safely land.{{cite book|last1=Launius|first1=Roger D.|last2=Jenkins|first2=Dennis R.|title=Coming home : reentry and recovery from space|date=2012|publisher=National Aeronautics and Space Administration|location=Washington, DC|isbn=978-0-16-091064-7|page=178|url=https://books.google.com/books?id=7k1sawDR-kEC&pg=PA178}}

A drawing in the Space/Aeronautics magazine from before the project's cancellation depicts the craft skimming the atmosphere for an orbital inclination change. It would then fire its rocket to resume orbit. This would be a unique ability for a spacecraft, as the laws of celestial mechanics ordinarily mean a change of plane requires an enormous expenditure of energy. The Dyna-Soar was projected to be able to use this capability to rendezvous with satellites even if the target conducted evasive maneuvers.

Unlike the later Space Shuttle, Dyna-Soar did not have wheels on its tricycle undercarriage, as rubber tires would have caught fire during re-entry. Instead Goodyear developed retractable wire-brush skids made of the same René 41 alloy as the airframe.{{cite book|last1=Heppenheimer|first1=T.A.|title=Facing the Heat Barrier: A History of Hypersonics|date=September 2007|publisher=National Aeronautics and Space Administration – History Division|location=Washington, DC|isbn=978-1493692569|page=150|url=https://history.nasa.gov/sp4232-part2.pdf|access-date=January 16, 2015|url-status=live|archive-url=https://web.archive.org/web/20130702213656/http://history.nasa.gov/sp4232-part2.pdf|archive-date=July 2, 2013|df=mdy-all}}

In April 1960, seven astronauts were secretly chosen for the Dyna-Soar program:{{cite book|last1=Pelt|first1=Michel van|title=Rocketing into the future : the history and technology of rocket planes|date=2012|publisher=Springer|location=New York|isbn=978-1461431992|page=269|url=https://books.google.com/books?id=4M9i-FXVKckC&pg=PA269}}

• Neil Armstrong (1930–2012; NASA) 1960–1962
• William H. "Bill" Dana (1930–2014; NASA) 1960–1962
• Henry C. Gordon (1925–1996; Air Force) 1960–1963
• Pete Knight (1929–2004; Air Force) 1960–1963
• Russell L. Rogers (1928–1967; Air Force) 1960–1963
• Milt Thompson (1926–1993; NASA) 1960–1963
• James W. Wood (1924–1990; Air Force) 1960–1963

Neil Armstrong and Bill Dana left the program in mid-1962. On September 19, 1962, Albert Crews was added to the Dyna-Soar program and the names of the six remaining Dyna-Soar astronauts were announced to the public.{{cite report|title=Astronautical and Aeronautical Events of 1962|date=June 12, 1963 |url=https://history.nasa.gov/AAchronologies/1962.pdf|page=195|publisher=NASA|access-date=April 30, 2023}}

By the end of 1962, Dyna-Soar had been designated X-20, the booster (to be used in the Dyna Soar I drop-tests) successfully fired, and the USAF had held an unveiling ceremony for the X-20 in Las Vegas.{{cite book|last1=Peebles|first1=Curtis|title=High frontier : the U.S. Air Force and the Military Space Program|date=1997|publisher=Air Force History and Museums Program|location=Washington, DC|isbn=0160489458|page=19|edition=Air Force 50th anniversary commemorative|url=https://books.google.com/books?id=cMgdYypcPc8C&pg=PA19}}{{cite book|last1=Jenkins|first1=compiled by Dennis R.|title=X-planes photo scrapbook|date=2004|publisher=Specialty Press|location=North Branch, MN|isbn=978-1580070768|page=95|url=https://books.google.com/books?id=uD8cBQAAQBAJ&pg=PA95}}

The Minneapolis-Honeywell Regulator Company (later the Honeywell Corporation) completed flight tests on an inertial guidance sub-system for the X-20 project at Eglin Air Force Base, Florida, utilizing an NF-101B Voodoo by August 1963."Fiery Crash of Drone Plane Kills Two, Injures One – Four Firemen Overcome in Wake of Blaze." Playground Daily News (Fort Walton Beach, Florida), Volume 16, Number 271, August 20, 1963, p. 1.

Boeing B-52C-40-BO Stratofortress 53-0399{{cite web|url=http://www.joebaugher.com/usaf_serials/1953.html|title=1953 USAF Serial Numbers|website=www.joebaugher.com|url-status=live|archive-url=https://web.archive.org/web/20110723051310/http://www.joebaugher.com/usaf_serials/1953.html |archive-date=July 23, 2011|df=mdy-all}} was assigned to the program for air-dropping the X-20, similar to the X-15 launch profile. When the X-20 was cancelled, it was used for other air-drop tests including that of the B-1A escape capsule.Spahr, Greg, "Might have beens",B-52 Stratofortress: Celebrating 60 Remarkable Years, Key Publishing Ltd., Stamford, Lincs., UK, 2014, page 38.

Besides the funding issues that often accompany research efforts, the Dyna-Soar program suffered from two major problems: uncertainty over the booster to be used to send the craft into orbit, and a lack of a clear goal for the project.File:Dyna-Soar on Titan booster.jpg

Many different boosters were proposed to launch Dyna-Soar into orbit.

The original USAF proposal suggested LOX/JP-4, fluorine-ammonia, fluorine-hydrazine, or RMI (X-15) engines, but Boeing, the principal contractor, favored an Atlas-Centaur combination. Eventually, in November 1959, the Air Force stipulated a Titan,{{rp|18}} as suggested by failed competitor Martin, but the Titan I was not powerful enough to launch the five-ton X-20 into orbit.

File:330-PSA-279-62 (USAF 167026) (21396347034).jpg

The Titan II and Titan III boosters could launch Dyna-Soar into Earth orbit, as could the Saturn C-1 (later renamed the Saturn I), and all were proposed with various upper-stage and booster combinations. In December 1961, the Titan IIIC was chosen,{{rp|19}}) but the vacillations over the launch system delayed the project and complicated planning.

The original intention for Dyna-Soar, outlined in the Weapons System 464L proposal, called for a project combining aeronautical research with weapons system development. Many questioned whether the USAF should have a crewed space program, when that was the primary domain of NASA. It was frequently emphasized by the Air Force that, unlike the NASA programs, Dyna-Soar allowed for controlled re-entry, and this was where the main effort in the X-20 program was placed.

On January 19, 1963, the Secretary of Defense, Robert McNamara, directed the U.S. Air Force to undertake a study to determine whether Gemini or Dyna-Soar was the more feasible approach to a space-based weapon system. In the middle of March 1963, after receiving the study, Secretary McNamara "stated that the Air Force had been placing too much emphasis on controlled re-entry when it did not have any real objectives for orbital flight".Geiger 1963, pp. 349–405. This was seen as a reversal of the Secretary's earlier position on the Dyna-Soar program.

Dyna-Soar was also an expensive program that would not launch a crewed mission until the mid-1960s at the earliest. This high cost and questionable utility made it difficult for the U.S. Air Force to justify the program.

Eventually, the X-20 Dyna-Soar program was canceled on December 10, 1963. On the day that X-20 was canceled, the U.S. Air Force announced another program, the Manned Orbiting Laboratory, a spin-off of Gemini. This program was also eventually canceled.

Another black program, ISINGLASS, which was to be air-launched from a B-52 bomber, was evaluated and some engine work done, but was eventually cancelled as well.[http://www.foia.cia.gov/docs/DOC_0000645397/0000645397_0049.gif "The U-2's intended successor: Project OXCART, 1956–1968."] {{webarchive|url=https://web.archive.org/web/20120308121747/http://www.foia.cia.gov/docs/DOC_0000645397/0000645397_0049.gif |date=March 8, 2012}} Central Intelligence Agency, December 31, 1968, p. 49. Retrieved: August 10, 2010.

Despite cancellation of the X-20, the affiliated research on spaceplanes influenced the much larger Space Shuttle. The final design also used delta wings for controlled landings. The later, and much smaller Soviet BOR-4 was closer in design philosophy to the Dyna-Soar,Marks, Paul. [https://www.newscientist.com/article/dn20664-cosmonaut-soviet-space-shuttle-was-safer-than-nasas.html "Cosmonaut: Soviet space shuttle was safer than NASA's."] {{webarchive|url=https://web.archive.org/web/20110803100705/http://www.newscientist.com/article/dn20664-cosmonaut-soviet-space-shuttle-was-safer-than-nasas.html |date=August 3, 2011 }} New Scientist, July 7, 2007. Retrieved: August 28, 2011. while NASA's Martin X-23 PRIME and Martin Marietta X-24A/HL-10 research aircraft also explored aspects of sub-orbital and space flight.Jenkins, Dennis R., Tony Landis and Jay Miller. [https://history.nasa.gov/monograph31.pdf American X-Vehicles: An Inventory—X-1 to X-50.] {{webarchive|url=https://web.archive.org/web/20081117011450/http://history.nasa.gov/monograph31.pdf |date=November 17, 2008 }} Washington, DC: Monographs in Aerospace History No. 31, SP-2003-4531, June 2003. The ESA's proposed Hermes crewed spacecraft was superficially similar to but not derived from the X-20.

File:X20 Dyna-Soar diagram.png

File:Dyna Soar launchers.png

{{Aircraft specs

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|crew=One pilot

|length ft=35.34

|span ft=20.8

|height ft=8.5

|wing area sqft=345

|empty weight lb=10395

|max takeoff weight lb=11387

|eng1 number=2

|eng1 name=AJ10-138

|eng1 type=rocket engine

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|max speed mph=17500

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}}

• The 1959 Twilight Zone season 1 episode titled "And When the Sky Was Opened" made reference to a spacecraft called the X20 which had a similar profile but could carry a crew of three.
• In 1962, the fifth book in Donald A. Wollheim's Mike Mars series, Mike Mars flies the Dyna-Soar, had the title character fly an emergency rescue mission in the Dyna-Soar.
• John Berryman's 1963 short story "The Trouble with Telstar" featured a Dyna-Soar being used to intercept communications satellites for repair.{{cite journal|last1=Berryman|first1=John|title=The Trouble with Telstar|journal=Analog Science Fact & Fiction|date=June 1963|url=http://www.gutenberg.org/files/30679/30679-h/30679-h.htm|access-date=May 14, 2015|url-status=live|archive-url=https://web.archive.org/web/20150924214025/http://www.gutenberg.org/files/30679/30679-h/30679-h.htm|archive-date=September 24, 2015|df=mdy-all}}
• The 1969 Hollywood film drama Marooned featured a rescue craft modeled somewhat after the Dyna-Soar (called the X-RV for eXperimental Rescue Vehicle) being hurriedly deployed to rescue astronauts aboard a crippled Apollo command capsule. This was lampooned in Mad Magazine as the XRT, the Experimental Rescue Thing.

{{Portal|Spaceflight}}

{{aircontent

|related=

• Manned Orbital Laboratory

|similar aircraft=

• ASSET – a subscale reentry test vehicle designed to verify the superalloy heatshield of the DynaSoar.
• BOR-4
• BOR-5
• Mikoyan-Gurevich MiG-105
• North American X-15
• Silbervogel

|lists=

|see also=

• {{annotated link|Boeing X-37}}
• Dream Chaser
• {{annotated link|Saturn-Shuttle}}
• Hermes
• {{annotated link|Hypersoar}}

}}

{{Reflist|30em|refs=

{{Harvard citation no brackets|Godwin|2003|p=186}}

{{Harvard citation no brackets|Godwin|2003|p=286}}

}}

{{Refbegin|30em}}

• Caidin, Martin. Wings into Space: The History and Future of Winged Space Flight. New York: Holt, Rinehart and Winston Inc., 1964.
• Dornberger, Walter R. "The Rocket-Propelled Commercial Airliner". Dyna-Soar: Hypersonic Strategic Weapons System, Research Report No 135.. Minneapolis, Minnesota: University of Minnesota, Institute of Technology, 1956.
• Duffy, James P. Target: America, Hitler's Plan to Attack the United States. Santa Barbara, California: Praeger, 2004. {{ISBN|0-275-96684-4}}.
• Dyna-Soar: Hypersonic Strategic Weapons System: Structure Description Report. Andrews Air Force Base, Maryland: Air Force Systems Command, 1961, pp. 145–189.
• Geiger, Clarence J. History of the X-20A Dyna-Soar. Vol. 1: AFSC Historical Publications Series 63-50-I, Document ID ASD-TR-63-50-I. Wright-Patterson AFB, Ohio: Aeronautical Systems Division Information Office, 1963.
• {{cite book|editor-last=Godwin|editor-first=Robert|title=Dyna-Soar: Hypersonic Strategic Weapons System|location=Burlington, Ontario, Canada|publisher=Apogee Books|year=2003|isbn=1-896522-95-5}}
• Houchin, Roy. U.S. Hypersonic Research and Development: The Rise and Fall of Dyna-Soar, 1944–1963. London: Routledge, 2006. {{ISBN|0-415-36281-4}}.
• {{cite book|last=Neufeld|first=Michael J.|title=The Rocket and the Reich: Peenemünde and the Coming of the Ballistic Missile Era|url=https://archive.org/details/isbn_9780029228951|url-access=registration|location=New York|publisher=The Free Press|year=1995|isbn=978-0-674-77650-0}}
• {{cite book|last=Strathy|first=Charlton G.|title=Dyna-Soar: Hypersonic Strategic Weapons System: Weapon System 464L Abbreviated Development Plan|year=1957|pages=38–75}}
• {{cite book|last=Yenne|first=Bill|title=The Encyclopedia of US Spacecraft|location=London|publisher=Bison Books|year=1985|isbn=978-5-551-26650-1}}

{{refend}}

{{Commons category|Boeing X-20 Dyna-Soar}}

• [https://web.archive.org/web/20160820130736/http://www.astronautix.com/d/dynasoar.html Dyna Soar] at Encyclopedia Astronautica
• [https://www.youtube.com/watch?v=IpO5q86Bqys Official United States Air Force film from the 1960 describing the spacecraft.]
• [https://web.archive.org/web/20160915090422/http://www.astronautix.com/t/tsienspaceplane1949.html Tsien Space Plane 1949] at Encyclopedia Astronautica
• [https://web.archive.org/web/20150924015719/http://www.friends-partners.org/partners/mwade/craft/tsie1978.htm Tsien Space Plane 1978]
• [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720065896_1972065896.pdf Transonic aerodynamic characteristics of the Dyna-Soar glider and Titan 3 launch vehicle configuration with various fin arrangements (PDF format) NASA report – April 1963]
• [https://archive.org/download/NASA_NTRS_Archive_20030067480/NASA_NTRS_Archive_20030067480.pdf American X-Vehicles: An Inventory X-1 to X-50, SP-2000-4531 – June 2003; NASA online PDF Monograph]
• [https://books.google.com/books?id=Nk8EAAAAMBAJ&pg=PA99 LIFE 22 Feb 1963 article about X-20 and the pilots training to fly it.]

{{Boeing military aircraft}}

{{Boeing model numbers}}

{{X-planes}}

{{USAF system codes}}

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{{Authority control}}

X-20 Dyna-Soar

Category:Cancelled American spacecraft

Category:Cancelled military aircraft projects of the United States

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Category:Partially reusable space launch vehicles

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Category:Tailless delta-wing aircraft

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