This is the follow up to the story we posted earlier today about the world’s fastest plane.

LOS ANGELES (AP) — An unmanned hypersonic glider developed for U.S. defense research into super-fast global strike capability was launched atop a rocket early Thursday but contact was lost after the experimental craft began flying on its own, the Defense Advanced Research Projects Agency said.

There was no immediate information on how much of the mission’s goals were achieved.

It was the second of two planned flights of a Falcon Hypersonic Technology Vehicle-2. Contact was also lost during the first mission.

The small craft is part of a U.S. military initiative to develop technology to respond to threats at 20 times the speed of sound or greater, reaching any part of the globe in an hour.

Nope, they didn’t bring the SR-71 Blackbirds out of mothballs, although they could, it’s still cutting edge technology and remains the worlds fastest plane that can outrun Soviet SAM’s and operate well above their range, flying in excess of Mach 3 (2000 mph), the real speed and operating range of those planes will never be made public. NASA still uses three of them.

No, the Blackbird didn’t get a second wind (unfortunately), I’m talking about an aircraft that is even faster. Six and a half times faster, and that’s all they’re letting on to the public. A plane known as the Falcon HTV-2. This thing is awesome:

By the time you finish reading this sentence, the Falcon HTV-2, the fastest plane ever built, could have flown 18 miles. It would get from London to Sydney in less than an hour, while withstanding temperatures of almost 2,000C, hotter than the melting point of steel.

At 3pm BST on Thursday , the US Defence Advance Research Projects Agency will launch the Falcon Hypersonic Technology Vehicle 2 on the back of a rocket from the Vandenberg Air Force Base in California. If all goes to plan, engineers will launch the Falcon HTV-2 to the edge of space, before detaching the plane and guiding it on a hypersonic flight that will reach speeds of 13,000mph (about 20 times the speed of sound) on its return to Earth.

The Falcon started life in 2003, part of a US military research project to build a plane that could reach (and potentially deliver bombs to) any part of the world in less than an hour.

The plane has been tested in computer models and wind tunnels, but they can only simulate speeds up to Mach 15 (11,400mph). A real test is the only way to determine if the plane will remain flying at high speeds.

Thursday’s flight will also test the carbon composite materials designed to withstand the extreme temperatures the plane will experience on its skin and also the navigation systems that will control its trajectory as it moves at almost four miles per second. Read the rest