Boeing X-20 Dyna-Soar

Le Boeing X-20 sur Wikipedia version anglaise :

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The X-20 Dyna-Soar ("Dynamic Soarer") was a [Vous devez être inscrit et connecté pour voir ce lien] (USAF) program to develop a [Vous devez être inscrit et connecté pour voir ce lien] that could be used for a variety of military missions, including [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], space rescue, [Vous devez être inscrit et connecté pour voir ce lien] maintenance, and [Vous devez être inscrit et connecté pour voir ce lien] of enemy satellites.

The program ran from 24 October 1957–10 December 1963, cost [Vous devez être inscrit et connecté pour voir ce lien]660 million, and was canceled just after spacecraft construction had begun.

Other spacecraft under development at the time, such as [Vous devez être inscrit et connecté pour voir ce lien] or [Vous devez être inscrit et connecté pour voir ce lien], were based on space capsules which returned on ballistic re-entry profiles.

Dyna-Soar was much more like the much later [Vous devez être inscrit et connecté pour voir ce lien]: it could not only be boosted and travel to distant targets at the speed of an [Vous devez être inscrit et connecté pour voir ce lien], it was designed to glide to earth like an airplane under the control of
the pilot.

It could land at an airfield, rather than simply falling to earth and landing with a parachute. Dyna-Soar could also reach earth orbit, like Mercury or [Vous devez être inscrit et connecté pour voir ce lien].

These characteristics made Dyna-Soar far more advanced in concept than the other [Vous devez être inscrit et connecté pour voir ce lien]
missions of the period.

Data collected during the X-20 program would prove useful in designing the Space Shuttle.

The much larger Shuttle would also be boosted into orbit by large rockets for launch, and the final design would also pick [Vous devez être inscrit et connecté pour voir ce lien] for controlled landings, but it (and the Soviet [Vous devez être inscrit et connecté pour voir ce lien]) would not fly until decades after the X-20 cancellation.

Background

The development of Dyna Soar can be traced back to [Vous devez être inscrit et connecté pour voir ce lien]'s [Vous devez être inscrit et connecté pour voir ce lien], a German bomber project of [Vous devez être inscrit et connecté pour voir ce lien].

The concept was to create a rocket-powered bomber that could travel vast distances by gliding to its target after being boosted to high speed (>5.5 km/s) and high altitude (50–150 km) by [Vous devez être inscrit et connecté pour voir ce lien] or A-9 rocket engines.


Essentially, these rocket engines would place the vehicle onto an exoatmospheric [Vous devez être inscrit et connecté pour voir ce lien]-like trajectory and then fall away.

However, when the vehicle reentered the [Vous devez être inscrit et connecté pour voir ce lien], instead of fully reentering, bleeding off its speed and landing, the vehicle would use its wings and some of its speed to generate [Vous devez être inscrit et connecté pour voir ce lien] and bounce the vehicle back into space again.

This 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 [Vous devez être inscrit et connecté pour voir ce lien] atmospheric lift meant that the vehicle could greatly extend its range over a ballistic trajectory using the same engines.

Such boost-glide systems could potentially strike at targets anywhere in the world (so called "antipodal bombers") at hypersonic speeds, be very difficult to intercept, and the aircraft itself could be small and lightly armed, compared to a typical [Vous devez être inscrit et connecté pour voir ce lien].

In addition, a boost-glide aircraft may be recoverable, acting as a manned bomber, or as an unmanned non-recoverable missile.

Following World War II, many German scientists were taken to the United States by the [Vous devez être inscrit et connecté pour voir ce lien]'s "[Vous devez être inscrit et connecté pour voir ce lien]".

Among them was Dr. [Vous devez être inscrit et connecté pour voir ce lien], the former head of Germany's wartime rocket program, who had detailed knowledge of the Silbervogel project.

Working for [Vous devez être inscrit et connecté pour voir ce lien], he attempted to create interest in a boost-glide system in the USAF, and elsewhere.

This resulted in the USAF requesting a number of feasibility and design studies — carried out by Bell, [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], and [Vous devez être inscrit et connecté pour voir ce lien] — for boost-glide vehicles during the early 1950s:

• Bomi (bomber missile);
  
• [Vous devez être inscrit et connecté pour voir ce lien] (HYpersonic Weapons Research and Development Supporting system);
  
• The [Vous devez être inscrit et connecté pour voir ce lien] reconnaissance vehicle; and
  
• Rocket Bomber "Robo".
  

Vue d'artiste X-20

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Development

On 24 October 1957, the [Vous devez être inscrit et connecté pour voir ce lien] issued a proposal for a "Hypersonic Glide Rocket Weapon System" (Weapons System 464L): Dyna Soar.

The proposal drew together the existing boost-glide proposals, as the USAF believed a single vehicle could be designed to carry out all the bombing and reconnaissance tasks intended for the separate studies, and act as successor to the [Vous devez être inscrit et connecté pour voir ce lien] research program.

The Dyna-Soar program was to be conducted in three stages: a research vehicle (Dyna-Soar I), a reconnaissance vehicle (Dyna-Soar II, previously Brass Bell), and a vehicle that would add 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 [Vous devez être inscrit et connecté pour voir ce lien] 18, the following year.

A robotic glide missile was to be deployed in 1968, with the fully operational weapons system (Dyna-Soar III) expected to be deployed by 1974.

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 [Vous devez être inscrit et connecté pour voir ce lien] was eventually finalized as the launch vehicle.

The Dyna-Soar was to be launched from [Vous devez être inscrit et connecté pour voir ce lien], Florida.

In April 1960, seven astronauts were secretly chosen for the Dyna-Soar program. [Vous devez être inscrit et connecté pour voir ce lien] and Bill Dana left the program in the summer of 1962.

On 19 September 1962, Albert Crews was added to the Dyna-Soar program and the names of the six Dyna-Soar astronauts were announced to the public:

• [Vous devez être inscrit et connecté pour voir ce lien] (NASA) 1960–62
  
• [Vous devez être inscrit et connecté pour voir ce lien], Jr. (Air Force) 1962–63
  
• [Vous devez être inscrit et connecté pour voir ce lien] (NASA) 1960–62
  
• [Vous devez être inscrit et connecté pour voir ce lien] (Air Force) 1960–63
  
• [Vous devez être inscrit et connecté pour voir ce lien] (Air Force) 1960–63
  
• [Vous devez être inscrit et connecté pour voir ce lien] (Air Force) 1960–63
  
• [Vous devez être inscrit et connecté pour voir ce lien] (NASA) 1960–63
  
• [Vous devez être inscrit et connecté pour voir ce lien] (Air Force) 1960–63
  

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 [Vous devez être inscrit et connecté pour voir ce lien].

Proposed Dyna-Soar I flights

• Dyna-Soar 1: 1 January 1966, no crew
  
• Dyna-Soar 2: 1 April 1966, no crew
  
• Dyna-Soar 3: 1 July 1966, 1 orbit, crew: James Wood
  
• Dyna-Soar 4: 1 October 1966, 1 orbit, crew: 1
  
• Dyna-Soar 5: 1 March 1967, 1 orbit, crew: 1
  
• Dyna-Soar 6: 1 May 1967, 1 orbit, crew: 1
  
• Dyna-Soar 7: 1 July 1967, 1 orbit, crew: 1
  
• Dyna-Soar 8: 1 September 1967, 1 orbit, crew: 1
  
• Dyna-Soar 9: 1 December 1967, multi-orbit, crew: 1
  
• Dyna-Soar 10: 1 March 1968, multi-orbit, crew: 1, last planned X-20 flight
  

Problems

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.

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

The original USAF proposal suggested [Vous devez être inscrit et connecté pour voir ce lien]/JP-4, fluorine-ammonia, fluorine-hydrazine, or RMI (X-15) engines.

Boeing, the principal contractor, favored an [Vous devez être inscrit et connecté pour voir ce lien]-[Vous devez être inscrit et connecté pour voir ce lien] combination, but eventually the Air Force stipulated a [Vous devez être inscrit et connecté pour voir ce lien], as suggested by failed competitor Martin.

However, the Titan I would not be powerful enough to launch the five-ton X-20 into orbit.

The Titan II and Titan III boosters could launch Dyna-Soar into Earth orbit, as could the [Vous devez être inscrit et connecté pour voir ce lien] (later renamed the [Vous devez être inscrit et connecté pour voir ce lien]), and all were proposed with various upper-stage and booster combinations.

While the Titan IIIC was eventually chosen to send Dyna-Soar into space, the vacillations over the launch system delayed the project as it 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 manned space program, when that was the primary domain of NASA.

However, 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 19 January 1963 the [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], directed the 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".
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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 manned mission until the mid-1960s at the earliest.

This high cost and questionable usefulness made it hard for the Air Force to justify the program.

Eventually, the X-20 Dyna-Soar program was canceled on 10 December 1963.

Description


The overall design of the X-20 Dyna-Soar was outlined in March 1960. It had a low-wing delta shape, with [Vous devez être inscrit et connecté pour voir ce lien] for control rather than a more conventional tail.

The framework of the craft was to be made from the [Vous devez être inscrit et connecté pour voir ce lien] "super alloy", as were the upper surface panels.

The bottom surface was to be made from [Vous devez être inscrit et connecté pour voir ce lien] sheets placed over insulated René 41, while the nose-cone was to be made from [Vous devez être inscrit et connecté pour voir ce lien] with [Vous devez être inscrit et connecté pour voir ce lien] rods.

Due to the changing requirements, various forms of the Dyna-Soar were designed, but all variants shared the same basic shape and layout.

A single pilot sat at the front, while an equipment bay was situated behind.

This bay contained either data-collection equipment, weapons, reconnaissance equipment, or (in the X-20X "shuttle space vehicle") a four-man mid-deck.

After the equipment bay was the transition-stage rocket engine, which was used to maneuver the craft in orbit or fired during launch as part of an abort.

This trans-stage would be jettisoned before descent into the atmosphere. While falling through the atmosphere an opaque [Vous devez être inscrit et connecté pour voir ce lien] would protect the window at the front of the craft.

This heat shield would then be jettisoned after [Vous devez être inscrit et connecté pour voir ce lien] so the pilot could see, and safely land.