According to a report published by Popular Mechanics, Lockheed-Martin won a contract valued at $147 million to develop, build, field and test a Mach 20 capable weapons system that could strike a target anywhere around the world in less than an hour. The goal, it goes on to say, “is to create a high-speed delivery system that could bomb targets thousands of miles away in an hour or less. It’s similar to what other countries, including Russia and China, are working on.
Tactical Boost Glide (TBG) will be an air-launched boost glide weapon system. The TBG itself is a aerodynamic, arrowhead-shaped vehicle fitted on the nose of a rocket. The rocket in turn is carried by a large aircraft such as a B-52 bomber, which would carry the rocket to high altitude and then launch it. The rocket boosts TBG to an even higher altitude, whereupon a scramjet or ramjet kicks in and quickly accelerates it up to hypersonic speeds. TBG then glides unpowered the rest of the way to the target.
How fast will TBG go? A nearly identical program concluded in 2011 reached speeds of Mach 20. At that speed, a hypersonic vehicle could travel from New York City to Los Angeles in 12 minutes, or London to Sydney in 49 minutes.
Hypersonic is the next frontier in weaponry. The super-fast speeds could make it possible to destroy a faraway but time-critical target—say, a North Korean missile fueling on the launch pad or a terrorist meeting in a remote location. Hypersonic speed also makes interception very difficult—and makes the actual vehicle a weapon when the kinetic energy of an object traveling at Mach 20 is transferred to a target.
Boost glide systems are difficult to shoot down. Their high speeds reduce reaction times, giving the defender less time to respond to the incoming threat. The launch profile of boost glide weapons is much like a traditional ballistic missile but stops short of entering low-earth orbit. This makes them tricky targets for existing, slower-moving interceptor missiles.
According to Defense Advanced Research Projects Agency (DARPA), which awarded the contract, Tactical Boost Glide will build on “knowledge and lessons learned from development and flight testing of previous boost glide systems, including the Hypersonic Technology Vehicle 2.” HTV-2 was that previous Mach 20 hypersonic program that last flew in 2011 for nine minutes. The stress of flying at Mach 20 subjected it to shockwaves one hundred times what it was designed to endure, as well as temperatures of up to 3,500 degrees Fahrenheit, before it was intentionally ditched in the Pacific Ocean.
Hypersonic weapons are also the next arms race. China is working on its own hypersonic weapon, the DF-ZF, which uses a DF-21 intermediate range ballistic missile instead of TBG’s bomber and rocket system. DF-ZF has been tested seven times, the latest in April 2016, with six tests judged by outsiders as successes. China’s hypersonic weapon travels at a more modest Mach 5 to Mach 10. The Russian Yu-71 system has been tested five times, with four failures.”
Obviously, such a system would be unmanned since it is inconceivable that a man could survive traveling at such incredible speeds while transiting low-earth orbit. And, if the vehicle is designed as an all-inclusive kinetic energy weapons system, then it would mean that the pilot was forfeiting his life in the process of carrying out the mission, perhaps other competing nations are willing to pay if they have similar systems in mind that are traveling at less stressful speeds, as PM suggests.
Of course, all of this falls under the purview of the recently announced doctrine dubbed Prompt Global Strike and flies in the face of MAD (Mutual Assured Destruction), first put forth in the 1950s and obviating the need for huge atomic arsenals. Prompt Global Strike (PGS) is a United States military effort to develop a system that can deliver a precision-guided conventional weapon airstrike anywhere in the world within one hour, in a similar manner to a nuclear ICBM. Such a weapon would allow the United States to respond far more swiftly to rapidly emerging threats than is possible with conventional forces. A PGS system could also be useful during a nuclear conflict, potentially replacing the use of nuclear weapons against 30% of targets. The PGS program encompasses numerous established and emerging technologies, including conventional surface-launched missiles and air- and submarine-launched hypersonic missiles, although no specific PGS system has yet been finalized as of 2015.