A new U.S. launcher based on strategic missile hardware made its successful suborbital debut April 22, but the U.S. Defense Advanced Research Projects Agency (DARPA) lost contact with the payload, an experimental hypersonic vehicle, soon thereafter, the agency said April 23. DARPA’s Falcon Hypersonic Technology Vehicle (HTV)-2 was the first in a series of flight experiments meant to demonstrate technologies that could be the foundation for the United States’ next long-range conventional missile. It was launched from Vandenberg Air Force Base, Calif., atop a Minotaur 4 rocket. Built by Lockheed Martin Corp., the HTV-2 craft was supposed to glide over...