US Army fires fastest gun to study rain effects at hypersonic velocity

The US Army’s Aerophysics Research Facility (ARF) has successfully conducted hypersonic tests using one of its fastest light gas guns to validate a newly developed rainfield simulator. This simulator is designed to model how vehicles behave when traveling through rain at hypersonic speeds, a critical factor for understanding extreme flight environments. The facility’s largest gun, a 254-millimeter light gas gun, can fire projectiles up to 1.9 miles per second (3 km/s), with smaller projectiles reaching speeds above 3.7 miles per second (6 km/s). The rainfield system produces controlled streams of water droplets with adjustable size, spacing, and density, allowing detailed study of rain effects on hypersonic vehicles. Recent tests, including a notable December 11 experiment using a non-spherical projectile, have yielded high-quality data and demonstrated reliable test execution. Earlier experiments involved launching nylon spheres at speeds near Mach 8 through artificial rainfields to evaluate advanced imaging and diagnostic tools