The Department of Defense recently awarded a $44 million contract to the Miltec Corporation, of Huntsville, Alabama. A low-key defense contractor located in the heart of American rocket country, Miltec produces very fast things: hypersonic weapons for the U.S. Army. Hypersonic weapons—missiles that can go five or six times the speed of sound—promise a uniquely American answer to warfare: a purely technological, pushbutton solution to the need to kill something.The U.S. isn’t the only power developing hypersonic weapons. Hypersonic weapons are the new arms race, with the United States, Russia, India and China all racing to develop them. Some hypersonic weapons are boosted to target atop intercontinental ballistic missiles, the same missiles designed to carry nuclear warheads in a nuclear war.What could possibly go wrong?Hypersonic is the new supersonic, a frontier of speed dreamed of but not yet conquered. Hypersonic weapons travel at extremely high speeds, anywhere from 3,840 to 16,250 miles an hour. A hypersonic weapon launched from New York could reach Moscow in less than 40 minutes. (By comparison, a Boeing 777 would make the same trip in eight and a half hours.)Miltec’s contract is for development of the so-called Advanced Hypersonic Weapon (AHW). The “weapon”--a cone-shaped object with winglets--is launched on top of a repurposed Poseidon nuclear missile. Using the “boost glide” method, the weapon is boosted 60 miles high, then glides at five times the speed of sound to within 30 feet of the target.A 2011 test flew 2,400 miles--from Hawaii to the Marshall Islands--and was considered a partial success. A new test is scheduled in August, and we can look forward to another in 2019.Washington’s hypersonic obsession—part of a larger concept dubbed Prompt Global Strike—is not new. Oddly enough, it was initially conceived as a weapon for the Global War on Terror. “PGS was conceived in the early 2000s to deal with a very specific problem,” explained Brian Weeden, technical advisor at the Secure World Foundation, “how to attack a high priority, time-sensitive target such as a meeting between high-level terrorists or theft of nuclear weapons anywhere in the world.” The Army’s Advanced Hypersonic Weapon is being developed under the Prompt Global Strike umbrella.There are problems operating at such incredible speeds. Friction between air and the weapon creates temperatures of up to 3,500 degrees Fahrenheit, hot enough to melt steel. Air itself becomes an obstacle--as the Defense Advanced Research Projects Agency inelegantly puts it, ”Air doesn’t travel around you--you rip it apart.” Finally, traveling at speeds of up to 3.6 miles per second makes guidance, navigation, and control tricky problems.Outside of Prompt Global Strike, NASA is developing a separate system for the Air Force that straps a hypersonic weapon onto a powerful jet engine and launches it from an aircraft. This is the technology behind NASA’s X-51A Waverider, which in 2010 reached Mach 5, or roughly 3,700 miles an hour for approximately 200 seconds.Hypersonic drones, like the drones before them, are the latest innovation in push-button warfare. Both kill the enemy remotely at long distances with minimal human involvement. A hypersonic weapon operator may be a thousand miles from the weapon he or she launches, and thousands more from the target.But like drones, there is a trade-off involved, one not as apparent to the operator than to those that risk becoming collateral damage. As convenient as drone warfare has been, the distance between the operator and the target is part of the reason more than 400 civilians have been killed in drone strikes in the last decade. Used in battle, hypersonics could exact a similar toll.The United States was the first to conduct large-scale hypersonic weapons research, but other nations are racing to catch up. The U.S. has shown that such weapons are technically feasible, but in doing so has also created a situation where rivals must research their own... or risk being outclassed in wartime. "Ultra-fast hypersonic weapons may be able to reach Russian territory virtually in no time to accurately hit strategic facilities, and we shall have nothing to fight back with," a Russian deputy defense minister told Itar-TASS in 2013.Unsurprisingly, Russia has started work on hypersonic weapons. In 2012, Russian Deputy Prime Minister Dimitry Rogozin stated, “I think we need to go down the route of hypersonic technology and we are moving in that direction and not falling behind the Americans.” Russia has announced that PAK-DA, Russia’s next-generation long-range bomber, will carry hypersonic missile, and Russia plans to develop a working model by 2020. That’s unlikely; hypersonics is a notoriously tough science to master; but the declaration speaks to Moscow’s ambitions.China has also entered the hypersonic race. On January 9, China tested a hypersonic boost glide system conceptually similar to the Army’s AHW, known to U.S. intelligence as the WU-14. China is already developing DF-21D “carrier killer” missiles, ballistic missiles modified to attack American aircraft carriers and create a “no go” zone for the U.S. Navy. Both types of weapons are difficult to shoot down, and adding hypersonic glide weapons to China’s arsenal would make the U.S. Navy’s job of keeping carriers afloat much harder.Even India is developing hypersonic weapons, with the development of the Brahmos II missile. Brahmos II is expected to fly at speeds of up to Mach 7, but is limited by international agreements to relatively short ranges, making it primarily useful against ships and ground targets.The result of all this is a classic arms race. As the Russian defense minister noted, the big powers all have to either develop hypersonic weapons or risk becoming outclassed. Nuclear weapons could prove the only way for it to retaliate in-kind, and nobody wants that.Another worry with hypersonic weapons is that the launch of ICBMs carrying hypersonic weapons would--at least initially--look identical to the launch of ICBMs carrying nuclear weapons. A frightened country could be prompted to quickly retaliate with nuclear weapons. Proponents claim there are ways to distinguish a conventionally-tipped boost glide missile from a nuclear-tipped ICBM in flight, but asking a country to wait and observe the trajectory of a possible nuclear missile without retaliating, especially in a crisis, may be unrealistic.Hypersonic weapons are here to stay. Proponents claim that hypersonic weapons will eventually becomes “socialized”--that is, we’ll all get used to them and the new dangers they bring. It will be up to American people to reconcile the likelihood of innocents killed with the need for a speedy, time-critical weapon system.In the meantime, Miltec owes the U.S. Army a working missile by June 5, 2019.