Alpha Draco

The Alpha Draco missile, also known as Weapons System 199D (WS-199D), was an experimental missile developed by McDonnell Aircraft in the late 1950s to investigate boost-glide reentry. Three test flights were conducted in 1959, of which two were successful.

Design and development
As part of the WS-199 project to develop new strategic weapons for the United States Air Force's Strategic Air Command, McDonnell Aircraft developed the Alpha Draco missile between 1957 and 1959. The purpose of the rocket was to establish whether a strategic missile using the "boost-glide" principle of propulsion could be practically used.

The Alpha Draco missile was a two-stage vehicle, the first stage comprising a Thiokol TX-20 solid-fuel rocket of the type used in the MGM-29 Sergeant theatre ballistic missile, and the second stage using a Thiokol TX-30 solid-fuel rocket. The payload vehicle was aerodynamically shaped, using the lifting body principle to provide aerodynamic lift; following burnout of the first stage, the vehicle would coast for a short time before ignition of the second stage, burnout of the second stage was followed by the vehicle entering the glide phase of flight, which would be terminated by a dive upon the target.

Operational history
Three test launches of the Alpha Draco vehicle were conducted during 1959, the missile being launched from a land-based gantry. The initial flight, on February 16, was successful; the second flight, one month later, also fulfilled its test goals. The final launch of the Alpha Draco on April 30, however, suffered a flight-control failure and was destroyed by range safety command. With the expenditure of the third and final vehicle, the program came to a halt, the project's cost having come to a total of approximately $5 million USD, the knowledge gained in the project proving invaluable to the development of re-entry vehicles for future intercontinental ballistic missiles.