File:Meck Island in the 1980s.jpg

English: After the Nike-X/Sentinel/Safeguard era, the Army continued developing ABM technologies and testing them at Meck Island in the Kwajalein Atoll. In this image we see the recently completed Site Defense Radar (SDR) system in the foreground, which was built on the reclaimed land that can bee seen as the lighter color area on the right half of the image.

SDR was basically an updated version of the Missile Site Radar (MSR), the larger building to its left. The much smaller building size demonstrates the improvements in radar and computer technology made over the ten years since the MSR was built in the late 1960s. The two fences seen on the lower right were radar reflectors that prevented stray rays from the MSR being reflected off nearby islands to the north. These "clutter fences" were common in earlier systems. The metal rails running up the sides of the MSR building are supports for a maintenance platform and were removed sometime after this photo was taken.

The Site Defense Program was part of ongoing studies to provide a last-ditch defence against attacks on the US Air Force's Minuteman missile silos. SDP sites would be equipped with an SDR and a number of Sprint II missiles positioned near the Minuteman silos. They would watch attacking warheads until the last possible second and only shoot at those that could be seen approaching a silo close enough to damage it. Others that could be seen falling outside the lethal radius would be ignored, allowing a small number of Sprints to deal with the warheads from a large number of ICBMs.

The photograph is taken looking south-southeast.