Hypervelocity
The study of projectile impacts with hypersonic velocities greater than several kilometres per second is an area of active research.
Such impacts are not yet used in military situations, but can arise from meteorite impact. The impact of extremely small, extremely fast particles is of interest in designing spacecraft to withstand erosion due to micrometeoroids and small orbital debris.
Ceramic fiber woven shields offer better protection to hypervelocity (>2 km/s) particles than aluminum shields of equal weight, but whipple shields developed by NASA offers the best protection.
One design for protection from small space debris and micrometeroids was the multi-layer shell of NASA's TransHab space habitation module. This technology was subsequently licensed by private company Bigelow Aerospace which is pursuing a similar scheme for a private space station design. Two Bigelow inflatable-technology space craft, Genesis I and Genesis II, built with proprietary extensions of the NASA technology, were launched in 2006. As of April 2009, both spacecraft were still operating nominally after more than 10,000 orbits and traveling over 270 million miles, demonstrating significant real-world validation testing of a fabric-based ballistic shield.
Accelerating projectiles up to such speeds on earth is currently difficult; light gas guns are currently the most common techniques for producing such speeds, although linear motors, railguns, coilguns and ram accelerators are also possibilities undergoing active research. NASA has been using two-stage light gas guns to simulate 2.2-cm diameter micrometeoid and orbital debris at velocities in excess of 7.5 km/s for decades and in 2005, Bigelow Aerospace utilized an earthbound test apparatus firing 1.7-cm-diameter aluminum projectiles into its inflatable spacecraft multilayer shield technology at 7 km/s.
See also Kinetic energy penetrator.
Read more about this topic: Terminal Ballistics