GAPA Launch Site and Blockhouse

This site is significant as the original launch site for the United States Air Force’s first supersonic guided missile, which was named the Ground-to-Air Pilotless Aircraft (GAPA). Thirty-eight two-stage GAPA solid-rocket-propelled aerodynamic test vehicles were launched by the Boeing Airplane Company from this site between June 13, 1946, and July 1, 1947. Stable supersonic flight was first achieved by GAPA test Vehicle 600 Series, Serial Number 10 on August 6, 1946. The GAPA program was subsequently transferred to Holloman Air Base in New Mexico, where an additional 73 missiles, propelled by various combinations of ramjet engines and solid and liquid rockets, were launched between July 24, 1947 and May 9, 1950.

GAPA was the lineal ancestor of the Air Force’s Bomarc air defense missile, which first flew on September 10, 1952, and is still in limited service 28 years later. The original GAPA launch site in Utah was the birthplace of the United States Air Force supersonic missile flight test program.

The GAPA Launch Site and Blockhouse was added to the National Register of Historic Places (#80003972) on August 26, 1980.

Reinforced concrete, semisubmerged blockhouse and launch pad. The Blockhouse is in original condition, except for damage caused by a single act of vandalism, to wit: entry door blown off hinges, glass viewports gone, hole blown in concrete floor and walls cracked, all apparently from a single explosive charge placed on blockhouse floor.

Reinforced concrete launch pad in same condition as when site was abandoned in July 1947. Steel launch tower no longer present.

The GAPA launch site and blockhouse is located three miles east and seven miles north of Knolls, Utah. The site includes the reinforced concrete launch pad approximately 100′ x 100′. The 40 foot steel tower, used in the launching moves, has been removed. Approximately 300 feet south of the launch pad is the original blockhouse from which the GAPA missiles were launched by remote control. The blockhouse remains in original condition except for damage done when an explosive charge was set off on the blockhouse floor. The explosion blew the entry door off its hinges, broke the glass view-ports, cracked the walls and left a hole in the concrete floor. The blockhouse is build of concrete, rises six feet above the ground level and is approximately 40 feet x 40 feet in size.