Although both programs saw a number of test launches in the 1960s, they had many drawbacks, one of them being that the nuclear blast would in all probability have crippled every other satellite, friendly or not, within a radius of several thousand kilometers. They also would have offered little or no protection against the Soviet Fractional Orbit Bombardment System (FOBS), a single-orbit nuclear weapon delivery system that was considered to be the main Soviet space-based threat against the US. Program 505 was canceled in 1966 and Program 437 was formally terminated in 1975, although it had lost most of its operational capacity after a hurricane hit Johnston Island in 1970.

The fact that the Russians spent significant resources on defending their military space stations shows that they either grossly overestimated the capabilities of these systems or had poor intelligence on future American ASAT systems. Sheer paranoia may also have come into play here, as it did in the 1976 decision to go ahead with Buran, the equivalent of the US Space Shuttle. That decision was largely driven by a twisted perception of the shuttle’s military potential.