The U.S. military’s more than decade-old effort to produce a hypersonic global strike weapon just took a big step forward and a big step back. On April 20, the Defense Advanced Research Projects Agency, or Darpa, published the results of an engineering review of a key hypersonic vehicle test.
On August 11, Darpa launched Hypersonic Test Vehicle 2, a wedge-shaped robotic craft meant to reach 20 times the speed of sound and travel for 30 minutes. HTV-2, boosted into the upper atmosphere by a Minotaur rocket, flew for only nine minutes before crashing into the Pacific Ocean. A previous test in 2010 using a similar test vehicle also ended in failure nine minutes into the flight.