YouTube: https://youtu.be/_dKfitikKM8
The US Defense Advanced Research Projects Agency (‘DARPA’) recently announced it seeks innovative proposals to help advance its hypersonic missile countermeasures program.
The proposals would seek to advance DARPA’s efforts to protect against the use of hypersonic missiles by countries such as Russia and North Korea that have developed and tested such missiles.
Presently, two types of hypersonic missiles and technologies exist. One type is a cruise missile like existing cruise missiles except for the ability to travel at hypersonic speed (five times the speed of sound). The other type is a ‘boost-guide’ missile. Both weapons are considered too fast to detect and have great destructive capabilities. Both weapons also are subject to significant changes in airflow that occur at hypersonic speeds (‘hypersonic cross flows’).
A boost-guide missile contains both the defensive weapon and a booster rocket that propels the weapon to hypersonic speed and then detaches. The weapon then glides to its destination and can use lift, or the upward acting force on an airfoil, to aide guidance.
DARPA’s current efforts focus on defending against boost-guide missile attacks and countering the weapon during its glide phase (hence, ‘Glide Breaker Program’). Under Phase 1 of the program, two prototype defensive missiles - or kill vehicles - were designed that use a divert attitude control system (‘DACS’). A DACS is a propulsion system that allows intercepting targets with great accuracy and reliability. According to DARPA, testing in Phase 1 included component tests and static hot-fire demonstrations of the DACS prototypes.
DARPA indicates Phase 1 represents a significant and crucial step. However, Phase 1 did not explore effects that occur in the endoatmosphere, or lower earth atmosphere. These effects include controlling the kill vehicle in the presence of jet interaction effects at conditions relevant to the operation of Glide Breakers. Jet interaction effects are effects between DACS jets and hypersonic cross flows. Accordingly, DARPA now seeks Phase 2 proposals that would include conducting wind tunnel and flight testing. If Phase 2 results are successful, they will inform further research, design and model development of a hypersonic weapon interceptor, and help the US bridge existing technological gaps.
