Author: Zvedre, Y. K.
Published in National Security Journal, 09 July 2020
One of the early attempts to use outer space for attacking targets on the ground was the development by the Soviet Union of the Fractional Orbital Bombardment System (FOBS) that was based on the R36 ICBM, and was made operational in 1968 as R36 Orbital (R36-O). The FOB vehicle was to be launched from the Soviet Union, aimed due south into an elliptical, low-Earth orbit and to de-orbit at a prescribed point. It would then traverse southern polar areas circumventing the US ground-based early warning radar installations which were oriented to track Soviet ICBMs on trajectories over the North Pole, to strike the US via the “backdoor”.4
The FOBs major drawbacks were the need to wait for the right moment to deliver an effective strike at a prescribed target and the system’s low reliability. This ultimately led to the US rejecting the idea of developing this type of space attack weapon. Instead, the view prevailed among the political and military leaders that a “classic” ICBM was a more reliable solution for ensuring nuclear deterrence. The 1979 Soviet-US Strategic Arms Limitation Treaty II (SALT II) strictly prohibited orbital nuclear bombardment systems, putting an end to further development of the Soviet FOBS. Accordingly, the R36-O missiles were decommissioned in January 1983. Similar provisions were also included in the 1991 Strategic Arms Reduction Treaty I (START I).5
Among the concepts the US tested and (for a brief time) deployed was the Nike Zeus AMB/ASAT weapons system developed during the late 1950s and early 1960s. While its two major versions were designed to intercept ICBMs in the upper atmosphere with a nuclear warhead, a third was produced and tested successfully for ASAT duties. From 1963 to 1966 Nike-Zeus ASAT missiles, which provided intercepts at altitudes of up to 250 km, were deployed at the ABM test range in Kwajalein Atoll in the Pacific Ocean. About the same time, the US Air Force (USAF) had also deployed Thor intermediate-range ballistic missiles which were based at Johnston Island in the Pacific Ocean in an ASAT role. Despite performing the same mission, the two systems complemented each other, the Nike Zeus being a faster and more reactive missile, but limited by its range. The Thor was a slower and less agile missile due to its liquid propellants, but it had a much greater range of up to 700 km.6
In addition to KEWs, research in the US was also focused on the systems based on directed electromagnetic energy, including a nuclear-explosion powered X-ray laser, and more conventional lasers including the idea of a satellite with a fixed laser and a deployable mirror for targeting. Those systems were sensitive to weather conditions and had limited range but among their advantages were the ability to attack a satellite target with varying intensity, just partly damaging its sensors or blinding it, whereas kinetic- kill weapons were designed to totally destroy their target. The facts about the US research on lasers were highlighted by Soviet propaganda, notwithstanding that from the 1970s onward the Soviet Union itself was actively involved in research and development of directed energy weapons. It experimented with large ground-based ASAT lasers that could pose a significant threat to both satellites and ballistic missiles.