The Pentagon has been working for nearly a decade on an audacious plan to strike anywhere on the planet in less than an hour. Wednesday could prove to be the do-or-die moment for that plan. At approximately 7 a.m. PDT, a three-stage Minotaur IV Lite rocket is scheduled to lift off from Vandenberg Air Force Base in California. It will puncture the atmosphere, and then release an experimental aircraft. That aircraft, known as the Falcon Hypersonic Technology Vehicle 2, will then come hurtling back to Earth at nearly 20 times the speed of sound, splashing down near the Kwajalein Atoll in the Pacific Ocean, approximately 4,100 miles away. Total flight time: about 30 minutes. That is, if the flight goes as planned. The first HTV-2, launched by Pentagon bleeding-edge research arm Darpa in April of 2010, disappeared over the Pacific after just nine minutes of flight. The vehicle was never recovered.