BMEWS – Ballistic Missile Early Warning System

Contributed by Stu Levy

The primary objective of this system was to detect an ICBM [Inter Continental Ballistic Missile] attach from the Soviet Union and would be electronically connected to NORAD [North American Air Defense Command].

BMEWS [Ballistic Missile Early Warning System] was the first (I think) all solid-state radar system built by the Defense Department. By solid state, I mean transistors - this was pre-IC time. It was started in the early 1950s and completed sometime in the late 1950s. The central computer was an IBM predecessor to the 360 (I used to remember the number, but it has slipped away.)

The program manager was RCA, IBM supplied the primary computer, GE supplied three fixed radar systems. Scanning was by rotating waveguide and RCA supplied one tracking radar – the antenna rotated.

Three sites were built, the first in Thule, Greenland, the second and third in England and Clear, Alaska.

The IBM computer as I remember had a core memory of 64K: 64bit words and the ferrite core was immersed in an oil bath and kept at a constant temperature. Slight variations of temperature caused bits to drop.

We went on line in sometime in the late 50s, connected to NORAD and relayed to SAC. Shortly after going on line, the monitors in the operational room starting filling up with what the computer said was a mass raid of ICBMs from the Soviet Union. The air force operations officer confirmed this with NORAD and SAC was notified.

Shortly thereafter, the resident system engineer came into the operation room with a reference book open and in his hand – it was the moon. For the first time since the system went operational, the moon was in sight of the radars, and the reflections – multiple rep rates later – were accepted by the system and saturated it.

And so we failed our first test. The system did eventually go live again and was an integral part of our defense. Years later, after upgrades, it served as a satellite tracking system. Whether it is still use, I have no knowledge.