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X43-A on to Mach 10

Cat_Byte writes "On March 28 we read about the X43-A hitting Mach 7 with a successful scramjet test. Prior to that on June 2, 2001 the craft tore itself to pieces during a trial run. Well now they are preparing to hit Mach 10. The upcoming Mach 10 run of the X-43A appears to mark an end of the program. The seven-year, approximately $250 million Hyper-X program was created to provide unique "first time" data on hypersonic air-breathing engine technologies. "At Mach 7, the front leading edge of the vehicle would see about 2,400 degrees Fahrenheit. At Mach 10, its probably twice that -- twice the heat load essentially," Sitz explained FYI, Mach 10 is about 2 miles per second."

7 of 459 comments (clear)

  1. Re:Mach 10? by radixvir · · Score: 5, Informative

    FYI, he was referring to the episode of Star Trek Voyager, where they test out the new engine technology on the shuttle. It goes Warp 10 which apparently causes 2 of the characters to "evolve" into gecko-like creatures. another completely ridiculous plot that took place around the time of the episode where they found Amelia Earhart

  2. Previous test aborted... by bchernicoff · · Score: 4, Informative

    ...the craft tore itself to pieces during a trial run.

    I was under the impression that the Pegasus boost missle went out of control so they self-destructed it...not that there was a problem with the X-43.

  3. Re:Front leading edge.... by Xentax · · Score: 4, Informative

    On a serious note, there are at least technically multiple leading edges on most craft (including this one).

    There's the leading edge of the wings, the horizontal stabilizers, the vertical stabilizer, etc. A combat aicraft might have more leading edges for external hardpoints - really, the front-facing part of any protrusion from the fuselage. Whether the nose/front of the fuselage itself is 'technically' a leading edge or not.

    Xentax

    --
    You shouldn't verb words.
  4. eeerh... i hate to say this by Anonymous Coward · · Score: 5, Informative

    but Mach 10 won't be 2 miles per second because they are not flying at sea level.

    Mach number is the square root of the product of gamma, R, and T. Being:

    gamma a propertie of the gas (1.33~1.44 aprox for air),

    R the constant of the gas (universal R over Molecular Mass for every kilo ... )..... (sorry, i know it's bad expressed) being about 287.15 for air

    And T is the absolute temperature of the gas;
    According to the International Atmosphere model, the temperature of air drops 6.5K every kilometer until you reach 11Km, beyond it remains constant until 22km, where it again rises.

    So, if depending of the height (and particular condition of the day and the state of atmosphere) the Mach speed varies

    As i haven't seen at what height they are flying, you can calculate yourself the Mach speed if you find the numbers.

    So is very probable that they are flying at really great heights where the mach value greatly differs from sea level Mach, what is taught to children, as other poster suggested

    Values of temperature of atmosphere can be found looking for ISA model (International Standard Atmosphere)

    By the way, i am using SI; so, if you find a table with Farenhait (or whatever it is spelled) you can convert a farenheit degree to kelvin via:

    (TF-32)/1.8+273 = kelvin

    PD: Sorry for my bad english

    1. Re:eeerh... i hate to say this by gerardrj · · Score: 4, Informative

      I went and did some research to post the actual ground speed in miles per hour of the ship traveling at mach 10 at 95,000 feet and I learned an interesting thing which astonished me.

      Actually, until you get very high in the atmosphere the speed of sound stays relatively constant compared to the speed of sound at sea level. Pressure and density decrease, but so does temperature.

      You can plug in some number in a calculator at
      http://www.grc.nasa.gov/WWW/K-12/airplane/soun d.ht ml

      The actual ground speed number (assuming no head/tail wind) of travelling at mach 10 at 95,000 feet is 6,777MPH or 1.887 miles per second.

      Up until now I, perhaps like most, though that since pressure decreases exponentially with altitude, that the speed of sound must also decrease at some constant, or at least predictable, rate with altitude. This was a real eye opener for me.

      --
      Article X: The powers not delegated... by the Constitution...are reserved...to the people
  5. Re:Anyone... by larkost · · Score: 4, Informative

    At that speed a brick is a "lifting body". Reminds me of the F-15 a.k.a. the "Aluminum Lawn Dart" (or world's most expensive lawn dart) because if you turn off the engine thats what your flight path looks like.

  6. Re:But can it do... by krlynch · · Score: 4, Informative

    It is a true statement that a Parsec is a measure of distance. But that doesn't rule it out as a unit of time. Special Relativity tells us that time and distance units are interchangeable, because the speed of light is a constant value in all reference frames.

    So, while I'm sure the original Star Wars quote wasn't meant to delve into the intricacies of modern physics, it certainly isn't technically wrong. Of course, since a Parsec is about 39 years, I certainly wouldn't want to be piloting for that amount of time...