U.S. Navy vice Adm. Jon Hill, the head of the U.S. Missile Defense Agency, or MDA, says that the multi-purpose SM-6 missile is the only weapon in the country's arsenal at present that offers any ability to knock down highly-maneuverable hypersonic threats. The SM-6 is the first missile of its kind, with anti-air, anti-surface and sea-based terminal defense capabilities, which enable it to intercept ballistic and cruise missiles. The first SM-6 missile was deployed by the US Navy in December 2013. It is part of Raytheon’s STANDARD missile family, which also includes Standard Missile-1, Standard Missile-2 and Standard Missile-3.