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Hypersonic Test Aircraft Peeled Apart After 3 Minutes of Sustained Mach 20 Speed

coondoggie writes "DARPA's experimental Hypersonic Technology Vehicle (HTV-2), lost significant portions of its outer skin and became uncontrollable after three minutes of sustained Mach 20 speed last August. That was the conclusion of an independent engineering review board investigating the cause of what DARPA calls a 'flight anomaly' in the second test flight of the HTV-2. Quoting the report: 'The resulting gaps created strong, impulsive shock waves around the vehicle as it traveled nearly 13,000 miles per hour, causing the vehicle to roll abruptly. Based on knowledge gained from the first flight in 2010 and incorporated into the second flight, the vehicle's aerodynamic stability allowed it to right itself successfully after several shockwave-induced rolls. Eventually, however, the severity of the continued disturbances finally exceeded the vehicle's ability to recover.'"

10 of 191 comments (clear)

  1. Re:scientifically by dispersionrelation · · Score: 5, Insightful

    The technology exhibited here is completely independent of the fuel source on which it runs. Your comment misses the point.

  2. slashdot by Anonymous Coward · · Score: 5, Informative

    This is slashdot. The only point of comments now is off-topic nonsense, hopefully modded 'informative'

  3. Expert opinion by Anonymous Coward · · Score: 5, Interesting

    As a person who flies hypersonic aircraft for a living this is notable on several layers.

    1. They did a test and it went far past hypersonic (M5).

    2. They achieved M20, altitude adjusted

    3. All that happened after 3 minutes is the materials failed

    4. It lasted 3 minutes!

    To me this is a stupendous success.

    I am a hyper-critic of most of the hypersonic tests we all hear about.

    Spend more money on this.

    JJ

    1. Re:Expert opinion by chebucto · · Score: 5, Insightful

      The fact that they corrected the problems found in the first test, and have a clear idea about why the second test failed, speaks very well to this program. I look forward to reading more about it.

      --
      The English word fart is one of the oldest words in the English vocabulary.
  4. Re:Close to re-entry speed by Moofie · · Score: 5, Insightful

    Yes. Science and engineering are often advanced by never doing anything you are not absolutely certain will work perfectly.

    --
    Why yes, I AM a rocket scientist!
  5. Re:scientifically..or not by Anonymous Coward · · Score: 5, Informative

    Except for the fact it runs on hydrogen peroxide and methanol. Plus, I'm given to understand the proposed full scale version would run on hydrogen slush and LOX.... aka rocket fuel.

  6. Re:Which "technology"? by Korin43 · · Score: 5, Funny

    As far as I can tell, the "Rapid Unscheduled Disassembly feature" seems to be fully wind-powered.

  7. Glass half empty, or half full? by rts008 · · Score: 5, Insightful

    IMHO, this was not a failure, just another step forward. We learned something useful, to be explored/applied next.

    Good job, folks! Keep moving forward....

    --
    Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
  8. Re:WHAT THE FUCK IS THE ALTERNATIVE? by roc97007 · · Score: 5, Funny

    What I really want is a bicycle powered, mach 20 vehicle. And a unicorn. And some waffles.

    --
    Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
  9. Re:Close to re-entry speed by SkyratesPlayer · · Score: 5, Insightful

    This close to the bleeding edge, definitely. We have better models and more teraflops to run them than ever before, but real breakthroughs come from unexpected, unintuitive results. Remember how hard it was for most engineers to believe that mere foam could bash in a shuttle wing - until they fired an actual piece of foam at an actual leading-edge panel?

    Flying real hardware is still the only way to conclusively
    1. Learn Something (if it has problems) or
    2. Silence the critics (if it works fine).


    IMHO, while a good number of aerospace contracts can be criticized for either being pork or thinly veiled airliner-maker subsidies, that should be focused on those never producing an instrumented flight.