Quickie
Colonel
The F-15 missile was not a direct-ascent satellite kill. Tailing a low-flying satellite and shooting it down from behind is much easier than a direct-ascent interception.
The kinetic kill vehicle has to go head on with the target satellite for the reason that the vehicle's velocity is very much smaller than the target's orbital velocity. This is especially so in the case of the US ASAT test where the missile fired from a F-15 jet is relatively much smaller than a ground based ASAT's missile. The only question is how successful was the US's ASAT program back then.