Data Gleaned From "Global Strike" Glider Flight Before Crash

(Aug. 12) -The U.S. Hypersonic Technology Vehicle-2, shown in an illustration. The aircraft stopped transmitting data earlier than expected during a trial flight on Thursday and is believed to have crashed in the Pacific Ocean (U.S. Defense Advanced Research Projects Agency/Aviation Week).
(Aug. 12) -The U.S. Hypersonic Technology Vehicle-2, shown in an illustration. The aircraft stopped transmitting data earlier than expected during a trial flight on Thursday and is believed to have crashed in the Pacific Ocean (U.S. Defense Advanced Research Projects Agency/Aviation Week).

A U.S. hypersonic drone aircraft sent out information for more than nine minutes before an "anomaly" disrupted transmissions during a flight test on Thursday, the Defense Advanced Research Projects Agency said (see GSN, Aug. 11; U.S. Defense Advanced Research Projects Agency release, Aug. 11).

The Hypersonic Technology Vehicle-2 is one system being considered to provide the United States with the "prompt global strike" capability to deliver non-nuclear warheads to any location in the world within an hour. Washington could tap that asset to strike an Iranian atomic facility or hit a North Korean missile prior to liftoff, the New York Times reported. Such a capability might also be employed against a critical terrorist location if no other weapon could carry out a sufficiently rapid attack (Thom Shanker, New York Times, Aug. 12).

Preliminary findings suggest the aircraft crashed into the Pacific Ocean midway through its intended flight course, the Defense Department office said.

The glider started on its planned flight path and "transitioned to Mach 20 aerodynamic flight" after a video feed confirmed its detachment from a rocket, according to an agency press release. "This transition represents a critical knowledge and control point in maneuvering atmospheric hypersonic flight," the document states (U.S. Defense Advanced Research Projects Agency release).

Still, “there’s no way you can call it a success," one insider told Wired magazine. "Let’s be blunt about it” (Noah Schachtman, Wired, Aug. 11).

The Minotaur 4 booster rocket lifted off with the glider at 7:45 a.m. local time from Vandenberg Air Force Base in California.

“Here’s what we know,” Maj. Chris Schulz, who heads the glider program, said in the DARPA statement. “We know how to boost the aircraft to near space. We know how to insert the aircraft into atmospheric hypersonic flight. We do not yet know how to achieve the desired control during the aerodynamic phase of flight. It’s vexing; I’m confident there is a solution. We have to find it.”

The agency must address unique aerodynamic, aerothermal, and command-and-control issues in each stage of the glider's movement, Schulz said.

“To address these obstacles, DARPA has assembled a team of experts that will analyze the flight data collected during today’s test flight, expanding our technical understanding of this incredibly harsh flight regime,” he said. “As today’s flight indicates, high-Mach flight in the atmosphere is virtually uncharted territory” (U.S. Defense Advanced Research Projects Agency release).

The glider also failed nine minutes into its first trial flight, conducted in April 2010, the Times reported (see GSN, Aug. 19, 2010; Shanker, New York Times).

“Prior to flight, the technical team completed the most sophisticated simulations and extensive wind tunnel tests possible. But these ground tests have not yielded the necessary knowledge. Filling the gaps in our understanding of hypersonic flight in this demanding regime requires that we be willing to fly,” DARPA Director Regina Dugan said in the statement. “In the April 2010 test, we obtained four times the amount of data previously available at these speeds. Today more than 20 air, land, sea and space data collection systems were operational. We’ll learn. We’ll try again. That’s what it takes” (U.S. Defense Advanced Research Projects Agency release).

This week's test, though, was intended to be the final DARPA trial of the aircraft, Wired reported. The Air Force or another military service might be hesitant to take control of the program, given its setbacks, according to the magazine.

“Yes, we got this wonderful data set from the two flights. Yes, you can cross-reference it with the wind tunnel data,” an informed source said. “Whether that’s worth $308 million, I’m not so sure" (Schachtman, Wired).

The glider is theoretically suited to reach Los Angeles from New York City in under 12 minutes, Agence France-Presse reported. Such an aircraft could prove more capable of carrying out evasive movements than a conventionally armed ICBM, and experts said it does not pose the same risk of being inaccurately identified as a nuclear weapon and prompting an atomic retaliation (see GSN, April 7).

"The military has a long way to go before hypersonic vehicles are ready for deployment," Lexington Institute specialist Loren Thompson said (Agence France-Presse/Google News, Aug. 11).

August 12, 2011
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A U.S. hypersonic drone aircraft sent out information for more than nine minutes before an "anomaly" disrupted transmissions during a flight test on Thursday, the Defense Advanced Research Projects Agency said (see GSN, Aug. 11; U.S. Defense Advanced Research Projects Agency release, Aug. 11).