Pye Wacket
Pye Wacket lenticular missile prototype with early exterior control surfaces
Type	Experimental lenticular air-to-air missile
Place of origin	United States of America
Production history
Designer	Convair (General Dynamics)
Designed	1957
Produced	1957-1961
Specifications
Weight	510 lbs (230 kg)
Height	9 inches (23 cm)
Diameter	70 in (1.8 m)
Warhead	high explosive
Warhead weight	55 lb (25 kg)
Engine	Thiokol M58A2 solid-fuel rocket motor x 3 10200 lbs. nominal thrust x 3
Wingspan	70 in (1.8 m)
Propellant	solid rocket engine
Operational range	72 nm (133 km)
Flight ceiling	77,350 ft to sea level
Speed	Mach 6.5+
Guidance system	Midcourse: autopilot Terminal: infrared homing
Steering system	nitrogen-injected binary maneuvering thrusters
Launch platform	XB-70 Valkyrie supersonic strategic bomber (planned)

Pye Wacket was the codename for an experimental lenticular-form air-to-air missile developed by the Convair Division of the General Dynamics Corporation in 1957.

Contents 1 Genesis 2 Design 3 Cancellation 4 See also 5 References

[edit] Genesis

Project "Pye Wacket", officially known as the Lenticular Defense Missile (LDM) Program, was instituted in 1957 in response to a US Air Force request for a Defensive Anti-Missile System (DAMS) to protect the proposed B-70 Valkyrie supersonic strategic bomber from high-speed, high-altitude surface-to-air missiles (SAMs).

The Valkyrie's extreme speed and operating altitude provided excellent protection against the Soviet jet interceptor aircraft of the day, but the development of the first high-altitude Soviet SAM (the SA-2 Guideline) quickly eroded this technological edge. The SA-2, which had been in development since 1952, was showcased in the 1957 May Day parade, with CIA U-2 photoreconnaissance flights soon revealing hundreds of likely SA-2 battery sites in construction. Much to the alarm of US intelligence analysts, the missile was touted as having a maximum ceiling of 82,000 ft, more than high enough to engage any US aircraft in existence or development. Even the high-speed Valkyrie was now seen as seriously vulnerable before a single operational bomber was produced.

[edit] Design

In a desperate effort to improve the bomber's perceived survivability against missiles, the DAMS specifications called for an air-launched defensive missile capable of engaging incoming missiles at relative speeds of up to Mach 7, surviving a rate of acceleration between 60-250g, and able to undertake rapid terminal-phase guidance changes in any direction.

Since these requirements far outstripped the traditional missile design of the time, Convair designers at the Pomona, California Division envisioned a radical lenticular-shaped missile, designed to retain its speed and structural integrity at extremely high angles of attack (as would be required when intercepting a rapidly accelerating SAM from high altitude). The shape would also theoretically allow for near-perfect mass and weight distribution, giving the missile outstanding terminal agility.

Initial feasibility studies were conducted by Convair engineers at the Air Proving Ground Center at Eglin AFB and the Arnold Engineering Development Center at Arnold AFB, with the full contract being awarded to Convair in June 1959.

Continued testing led to the construction of several early wind-tunnel models featuring various external control surfaces, which soon proved inadequate at supersonic speeds. The first functional prototype, built 2 years into development, featured a bank of six nitrogen-injected binary maneuvering thrusters mounted at the rear of a magnesium-alloy disc airframe with a wedge-shaped vertical cross section. The powerplant was three Thiokol M58A2 solid-fuel rocket motors, each producing 10200 lbs. thrust, propelling the missile to a max speed of Mach 6.5 with a max range of 72 nm.

[edit] Cancellation

The Valkyrie's exorbitant price tag and increasingly poor survivability against SAMs (exacerbated by the embarrassing 1960 U-2 incident) eventually doomed the XB-70 project in favor of increased funding for intercontinental ballistic missiles, and it was canceled by President John F. Kennedy on 28 March 1961. The Pye Wacket project was presumably abandoned shortly thereafter, though no documents attesting to the fate of the prototypes or further use of the technology have been released.

[edit] See also

• XB-70 Valkyrie
• flying saucer
• surface to air missile

[edit] References

• Anderson, A. (March 1960). Force tests of lenticular configurations at supersonic speeds. (AD0315671).

• General Dynamics; Convair/Pomona Division (July 1961). Pye Wacket. Feasibility Test Vehicle Study. Summary. Volume 1. Reproduced by Defense Technical Information Center. Retrieved on May 22, 2009.

• Jenkins, Dennis R.; Tony R. Landis (2004). Valkyrie: North American's Mach 3 Superbomber, Specialty Press. ISBN 1580070728.

• Parsch, Andreas. Directory of U.S. Military Rockets and Missiles, Appendix 4: Undesignated Vehicles. "Convair Pye Wacket". Retrieved on May 22, 2009.

• US Air Force, History of the Arnold Engineering Development Center: July - December 1960. II-24, 5. Reproduced per request to Air Force Historical Research Agency. Retrieved on May 22, 2009.