James A. Van Allen, discoverer of the Earth’s radiation belts, died on Wednesday, aged 91.

Others will record Van Allen’s scientific achievements and the loved ones he leaves behind.

I remember Van Allen most, however, for how then-President John F. Kennedy invoked Van Allen’s repution to deflect brilliantly a tough question about the possible environmental consequences of an upcoming high altitude nuclear explosion:

QUESTION: Mr. President, it has been the stated policy, as you said earlier, for this government to restrict Outer Space for peaceful objectives only. Will not the proposed H-bomb explosion 500 miles up jeopardize this policy and objective?

THE PRESIDENT: No, I don’t think so. I don’t think so. I know there has been disturbance about the Van Allen belt, but Van Allen says it is not going to affect the belt. (laughter)

But it is a matter which we are—I have read the protests, and it’s a matter which we are looking into, to see whether there is scientific merit that this will cause some difficulty to the Van Allen belt in a way which will adversely affect scientific discovery, and this is being taken into very careful consideration at the present time. But I do—I think that—so that I want you to know that whatever our decision is that, in regard to the Van Allen belt, it will be done only after very careful scientific deliberation, which is now taking place, during this past week, and will go on for a period. In regard, generally, what we are attempting to do is to find out the effects of such an explosion on our security, and we do not believe that this will adversely affect the security of any person not living in the United States.

Kennedy’s wit was devastating—in fact, you really have to see Kennedy’s delivery to understand how completely he disarmed the press corps. The clip is the most memorable moment, to my mind, from Peter Kuran’s Nukes in Space.

In fact, one of of the nuclear tests, the 1.4 megaton STARFISH PRIME exploded at 400 km, did excite the Earth’s radiation belts, disabling 2 or 3 satellites.

Although some scientists felt the data from the explosion was well worth the lost space assets, Jerome Weisner, the President’s science advisor, prevailed upon Kennedy to restrict the altitude of future atomospheric nuclear tests. (All atmospheric nuclear tests would be prohibited by the 1963 Limited Test Ban Treaty).

You can view footage of Starfish Prime and the other Operation Fishbowl detonations at the DOE Historical Test Films site. You will want to make sure to check out the Operation Fishbowl explosions set to muzak.