Convair X-11

The Convair X-11/SM-65A Atlas/Atlas A was the first full-scale prototype of the Atlas missile, first flying on 11 June 1957.[21] It was a test model designed to verify the structure and propulsion system, and had no sustainer engine or separable stages. The first three Atlas A launches used an early Rocketdyne engine design with conical thrust chambers and only 135,000 pounds of thrust. By the fourth Atlas test, they were replaced by an improved engine design that had bell-shaped thrust chambers and 150,000 pounds of thrust.

The Convair X-11, also known as the SM-65A Atlas or Atlas A, was a full-scale prototype of the Atlas intercontinental ballistic missile (ICBM). It was designed to test the structure, propulsion system, and launch system of the Atlas missile. The first flight of the Atlas A took place on June 11, 1957.

Prototype Development

The Atlas A was not a production missile but a test vehicle to verify key components of the Atlas ICBM.

Early Engines

The initial Atlas A launches utilized an early version of the Rocketdyne engine with conical thrust chambers.

Engine Improvements

Later Atlas A tests saw the use of improved Rocketdyne engines with bell-shaped thrust chambers, enhancing thrust.

Test Flights

The Atlas A was subjected to several test flights at the Air Force Missile Test Center.

Operational Role

While the Atlas A was a prototype, the SM-65A Atlas ICBM, based on its design, became operational in 1959, marking a significant step in the Cold War arms race.

Unique Features

Unlike later Atlas versions, the Atlas A did not have a sustainer engine or separable stages, and it featured a single propulsion system with two Rocketdyne engines.

Launch Infrastructure

The Atlas ICBM, including the Atlas A, was housed in underground "silos" or hardened shelters across the US.

Missile Technology

The Atlas A represented a key advancement in missile technology, contributing to the development of ICBMs and their role in strategic defense.