quantities, in particular, P-Division measurement of . by detectors in a vacuum, and 4. Upper atmospheric physics information which could not all be satisfied in one shot. Included as two main possibilities would be a 50 at [50 kitometers and a Y2 or something larger at roughly 1,000 kilometers. The former shot would be the appropriate one for AEC purposes if only one of the two shots could be performed. In relation to the method of such high altitude testing it is noted that a device would be launched from Johnston Island in a Thor missile to about 150 kilometers at which altitude it would be turned on its side and fired. Diagnostics would be done from rockets at about 200 kilometers altitude launched from Mid-Way, Kawi, Christmas !sland, or Palmira or Jarvis. No observations would be made from other Johnston {sland missiles or from pods due to the fact that telemetry would then not have to face the problem of too high gamma and x-ray intensities and secondly, the intensity levels and those distances get closer to those that one might actually expect in space testing, and thirdly, it appears the neutron spectrum and intensity can be measured very nicely with a vaccum pack of something like a 1,000 miles. Obviously, other ground type measurements could be made from Johnston or other adjoining islands. Furthermore, in noting that the DOD proposes two high altitude shots, the AEC feels that neither shot would satisfactorily answer AEC questions but that they should be instrumented and about 15 or 20 instrumentation rockets will be flown against each of the three high altitude shots. Furthermore, Radchem sampling by rockets on the high altitude or space shot seems to be out of the question on this time scale. A letter from Ogle to Betts dated !7 November addresses the present capabiI- ities and plans for diagnostics in various test situations overseas. As for devices air-dropped or done by balloons, Fireball, Radchem, Alpha and

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