Tweeting HTV-2 (Updated)

Want to know what's happening minute-by-minute on today's Hypersonic Technology Vehicle test?

Well, DARPA has a tweet for that.

The Defense Advanced Research Projects Agency has been live-Tweeting (@DARPA_News) today's launch of the HTV-2. The program, which can get to speeds of Mach 20, is part of the Pentagon's Conventional Prompt Global Strike effort designed to strike worldwide targets in less than an hour.

After counting down to the launch, at about 7:45 a.m. Pacific Standard Time, DARPA_News tweeted: "We have lift-off of the Minotaur IV launch vehicle carrying the 2nd #HTV2 flight test vehicle." One minute later, DARPA let the Twitterverse know that in a few minutes the vehicle will leave the visual range of Vandenberg Air Force Base, CA tracking, where the launch took place.

"Confirmation of a successful #HTV2 separation from the Minotaur IV launch vehicle," DARPA tweeted right before 8 a.m. PST. This was followed by news that Pacific Tracker acquired the signal, and that the mission is on track with the vehicle entering the "glide phase." During this phase, the HTV-2 "performs maneuvers to test aerodynamic performance," according to a DARPA fact sheet.

But around 8:20 PST, a hiccup: "Range assets have lost telemetry with #HTV2. More to follow."

During the vehicle's first test in April 2010, the vehicle lost communication about nine minutes into the flight and crashed into the Pacific Ocean.

UPDATE (12:26 p.m.): DARPA's latest Tweet: "Downrange assets did not reacquire tracking or telemetry. #HTV2 has an autonomous flight termination capability. More to follow."