USS Zumwalt (DDG1000) destroyer was spotted undergoing its refit for CPS (Conventional Prompt Strike) boost-glide hypersonic missiles.
The plans to equip Zumwalt-class destroyers with hypersonic weapons in place of 155 mm AGS guns are going forward as the guns have been removed from the lead ship for launch cells for CPS missiles.
Following the realisation that the 155 mm AGS main guns are beyond the boundaries of cost efficiency with their astronomically expensive guided ammunition (Almost as much as an RGM-84 Harpoon anti-ship missile per unit), the USN has decided to repurpose Zumwalt as a medium-range strike ship rather than a gun-hauling fire support ship.
CPS is being developed based on the experiences gained from previous hypersonic boost-glide tests as the sea-based leg of the U.S. plans to implement hypersonic missiles in three domains.
The other two legs of the U.S.'s hypersonic boost-glide weapon plans are the land-based LRHW and a submarine-based missile. All three missiles use the same hypersonic glide vehicle dubbed Common Hypersonic Glide Body Block 1.
CPS and its derivatives consist of a two-stage booster to haul the hypersonic glide vehicle to high altitudes and hypersonic speeds.
The advantage of boost-glide type hypersonic missiles is mainly the greater difficulty of interception due to their small size, extreme speed, and altitude, which is too high for long-range air defence missiles and too low for exo-atmospheric interceptors.
The drastically lower drag due to low air density at such altitudes, coupled with speeds above Mach 5, allows these missiles to reach ranges of more than 1000 km, entering the medium-range regime.
