“So far, the only promising [boost phase] defense system concept has been a space based or satellite borne interceptor. Such a system requires many thousands of interceptors in space, but at a given instant only a small fraction will be in a position to attack. The economic feasibility of such systems is heavily dependent upon equipment reliability and upon enemy countermeasures.” ~ Harold N. Beveridge in his 1960 Advanced Research Projects Agency (ARPA) ‘Project Defender” report Read Full Story