Posted on behalf of George Wigmore.
Later today the US Defense Advanced Research Projects Agency (DARPA) will launch its latest hypersonic vehicle, the arrow-shaped Falcon Hypersonic Technology Vehicle 2 (HTV-2), in a bid to develop future hypersonic vehicles that can reach anywhere in the world with an hour.
Blasting off from Vandenberg Air Force Base in California sometime between 7am and 1pm PDT today, the Minotaur IV Lite launch vehicle will orient HTV-2 in the upper atmosphere before releasing it. Capable of reaching speeds in excess of 20,000 kilometres per hour, or Mach 20, as it glides through the earth’s atmosphere, HTV-2 will perform several manoeuvres to test aerodynamic performance, before diving into the Pacific Ocean, 6,500 kilometres from California.
HTV-2’s inaugural flight in April 2010 failed, though it did collect valuable data, mostly by highlighting necessary adjustments. In a statement released by DARPA, HTV-2 program manager, Chris Schulz says, “It’s time to conduct another flight test to validate our assumptions and gain further insight into extremely high Mach regimes that we cannot fully replicate on the ground.”
But how fast is the HTV-2 compared to other aircraft? The record for a manned air-breathing craft is still held by the Lockheed SR-71, which reached speeds of 3,540 kilometres per hour on 28 July 1976. Yet while HTV-2 is closer in speed to a Minuteman intercontinental ballistic missile (ICBM), which can travel at speeds of over 24,000 kilometers per hour, they all pale into insignificance when compared to the Space Shuttle, which reached speeds of 30,000 kilometers per hour during reentry.
As the last remaining prototype, a lot hinges on HTV-2’s mission, especially with no further plans to build another. But any information collected will help improve future hypersonic flight vehicle performance.
UPDATE 11/8/11: Despite much anticipation, yesterday’s launch of HTV-2 was scrapped last minute after poor weather conditions prevented lift-off. Launch has been rescheduled for later this morning, PDT time.
UPDATE 12/8/11: Following its launch on Thursday, Darpa’s latest attempt to fly the fastest aircraft ever built has failed for the second time. Launched from Vandenberg Air Force Base in California at 0745 Pacific Time, the Falcon HTV-2 was successfully released into the atmosphere, but only nine minutes of data was collected before signal was lost. The agency believes that the vehicle crashed into the Pacific Ocean.
Image credit: DARPA