Foreign Relations of the United States, 1958–1960, Volume III, National Security Policy; Arms Control and Disarmament, Microfiche Supplement

465. Memorandum From Panofsky to Killian¹

Washington, May 1, 1959

SUBJECT

• Preliminary Findings of the Working Group of the Panel on High Altitude Detection

At a meeting on 1 May 1959, a Working Group of the Panel on High Altitude Detection considered the problem of identifying nuclear explosions in the region between 50 and 100,000 kilometers. This region was chosen since it was believed this would eliminate the problems of both fallout and communications disturbances.

The Working Group came to the following preliminary conclusions:

1) Detection of unshielded bombs of low yield at distances of 100,000 kilometers is possible with high confidence from terrestrial stations by means of both direct emission of light and fluorescence of the upper atmosphere induced by bomb x-rays. Cloud cover will probably not reduce this capability substantially.

2) Identification should involve signals arising from some other effect than thermal radiation alone. Of the various possibilities, radar backscatter may be particularly significant since it does not necessarily depend on the thermal x-rays emitted from the bomb as do most of the other effects. Other identification aids are: a) magnetic field perturbations, b) modification of the Van Allen radiation as measured in a satellite, c) ionospheric perturbations, and d) direct radio signal.

3) Special problems exist in the very low altitude range (50–200 kilometers) where only one ground station might “see” (line of sight) the explosion. Consideration will be given to this problem.

4) Current judgment is that concealment of direct light emission is difficult but that concealment of the x-rays which give fluorescence radiation and ionospheric disturbances could be effective.

Individual members of the Working Group will prepare detailed papers on each of these methods which will be submitted to the Chairman within two weeks. These papers will present estimates of the capabilities, and, if possible, the availability and costs of each of these systems. A final meeting of the Working Group will be held within a month to prepare a general report covering the detailed conclusions on this problem.

Wolfgang K.H. Panofsky
Chairman, Panel on High
Altitude Detection

1. Source: Preliminary findings of the working group on high altitude detection. Secret. 2 pp. Eisenhower Library, White House Office Files, Additional Records of the Office of the Special Assistant for Science and Technology, Disarmament-Nuclear-Hi-Alt-Misc.