I was wondering how a missile interceptor was even possible in the 50s given the insane precision required to hit a bullet with a bullet at those speeds, but it actually uses a nuclear warhead.
Spartan used a 500 kT thermonuclear warhead, I believe. It was a special warhead designed to minimize immediate beta emission in the debris cloud (which would create ionization that would interfere with radar). To that end, the tamper in the H bomb's secondary was not uranium, but solid gold.
