In mid December 2001 a crash site on the Nevada Test Site was first observed and photographed from the air. In early January 2002, NTS personnel located the site and obtained aircraft identification information identifying the debris as being a Navy Regulus class missile.
Later in that same month the aircraft type was positively identified as a Chance Vought Regulus II, Model XR33M-N-9A missile. The debris identity was further verified on February 19, 2002 by Dr. David Stumpf, a member of the Titan Museum Board of Directors and author of the definitive reference on the Regulus missile program. It was concluded that the missile (GM-2010) had been launched from Point Mugu, California on May 1, 1958 and crashed "on approach" to Antelope Dry Lake landing site near Tonopah, Nevada. The cause of the crash is believed to be due to a failure of the inertial guidance system.
The Regulus I Assault Missile, or R.A.M., was a concept that grew out of the success of the Regulus I flight test program. Test pilots had demonstrated that the missile could be controlled, and even recovered, by pilots in chase aircraft. In 1955, the Navy sought to capitalize on their accomplishments by training carrier-based pilots to escort the missile to targets. Aircraft control of the Regulus I would effectively extend its range and, potentially, its accuracy. It would also allow the vessel which had launched the missile, which otherwise would have to remain on station and guide the missile to target, to escape the combat zone.
The nuclear armed Regulus I was a key part of the Navy's capabilities in the 50's, and R.A.M. pilots spent a great deal of time practicing their delivery duty and exercising the Navy's missile crews. Practice missiles, equipped with landing gear, were often recovered and flown again, and again, and again. Occasionally, a Regulus with a conventional warhead would be detonated as part of an exercise.
The chase planes would assume position astern of the missile, roughly a quarter of a mile away at about 220 knots, as the missile launched. The missile has to accelerate from zero to its flying speed and that allowed the chase plane to slide in, take control and stay with it, flying just above the missile on the right side, a technique pioneered during the test program.
War plans called for the missile and control jet to fly at about 35,000 feet until within radar range of the target "presumably an enemy fleet or shore installation" and then descend under the radar envelope. Then the pilot would fly the missile in, detonating it when it was right over its target. R.A.M. pilots were under few illusions about the survivability of their mission. For one thing, while they were flying towards a target, the aircraft carrier on which they were based would likely be attempting to sail as fast as possible in the opposite direction. For another, their aircraft would have to survive the proximity effects and shock wave of the Regulus' thermonuclear warhead with only five or six miles of separation.
In June of 1952, the Bureau of Aeronautics released an invitation to bid on improvement of the Regulus I missile and, one month later, revised the specifications to include a requirement that the airframe fly at mach 2 for the entire flight. Chance Vaught's experience with the Regulus I program led them to propose a totally new design, the Regulus II.
The Regulus II series airframes were built in three versions. The first ones (GM-2001 to GM-2007) used a Wright Aeronautical J65-W-6 turbojet engine and were utilized in the taxi-take off portion of the flight test program. The second version (GM-2008 through GM-236) used a General ElectricJ79-GE-3A and was utilized for fleet training. All of the remaining Regulus II's (GM-3001 through GM-3038) were utilized as tactical missiles.
The Regulus II warhead was developed in 1955 by LLNL. The warhead design later became part of a gravity bomb for carrier-based aircraft. The first flight of the XSSM-N-9 missile occurred on 29 May 1956. A production contract was signed in January 1958. On September 16, 1958, the U.S. Navy fired a Regulus II from the USS Grayback, the first and only such launching from a submarine. On December 18, 1958, the Secretary of the Navy cancelled the program in favor of the Polaris Missile Program.