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Second Test of X-43A Scramjet Tomorrow

pinkUZI writes "NASA says its new Hyper-X, a jet capable of flying some 5,000mph - seven times the speed of sound - will be ready to take a test cruise across the Pacific this Saturday. This is actually NASA's second attempt; the first, in 2001, failed when stabilizing fins flew off the plane's booster rocket and controllers ordered the craft destroyed. CNN has the story." NASA's mission web page has more information, photos, etc.

20 of 325 comments (clear)

  1. still need ... by pvt_medic · · Score: 4, Interesting

    the b-52 to launch the plane. Will they be able to develop on of there that can take off on its own? or will we always be launching them from the underbellies of a big plane.

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    1. Re:still need ... by Waffle+Iron · · Score: 4, Interesting
      The B-52 isn't the big deal. Instead, it's multimillion dollar conventional Pegasus rocket booster that gets the test vehicle up to speed. The Pegasus has been in use for a long time to launch small payloads into orbit; it's always dropped from an airplane.

      What I don't quite understand is why they need a rocket capable of reaching orbit just to get the X-43 up to ~mach 5 so it can start it's engines. It seems like overkill to me. I would suppose they only use the Pegasus's first stage; maybe they had some cheap spares laying around.

    2. Re:still need ... by alecks · · Score: 2, Interesting

      How do they catch it afterwards? Or do they let it fall in the ocean?

    3. Re:still need ... by trs998 · · Score: 5, Interesting

      Wouldnt it have a problem with wing size?

      flying at 5,000 mph, you'd basically have all the body lift yo'd need... the SR-71 (aka Habu or Blackbird) uses small wings and is very specialized.

      The SR-71 has tiny wings, and consists of 2 huge engines.. it also leaks fuel onto the runway until the body heats up to running temperature.

      The point being that the SR-71 has a very high take off and landing speed due to the small lift per mile figure. It will fly straight up and over a thousand mph until the engines run out of oxygen at nigh on 100,000 feet.

      A aircraft using the scramjet capable of 5,000 mph would have to have very small wings for low air resistance and wouldnt need large lift per mile.
      The ScramJet wouldnt work at low speeds, therefore the runway would have to be very long to take off using a conventional JATO (Jet Assisted Take Off) unit to get the ScramJet working. Getting a scramjet off the runway is going to be interesting!

      BTW, what engine does the proposed (Active?) Aurora reconissance/spy plane use? It's supposed to have a very high speed (~3000-4000 mph?)

    4. Re:still need ... by Anonymous Coward · · Score: 1, Interesting

      Actually, there is a second, less publicized part of the X-43 program. The X-43A-LS is a low-speed version of the Hyper-X, and it is designed to take off and land from a conventional runway. There are some differences in the two aircraft, though: the -LS has slightly larger wings and tails than the Hyper-X, due to the speeds that it flies at, and the propulsion system that it uses: the -LS uses a model aircraft turbine engine. More info on the X-43A-LS: www.accurate-automation.com.

    5. Re:still need ... by MrCocktail · · Score: 3, Interesting
      An article describing some sc/ramjet technology. For the impatient:


      The scramjet propulsion system uses different kind of technology than traditional rockets. Instead of carrying both fuel and oxygen to ignite, the scramjet uses oxygen in the atmosphere. To get the oxygen to ignite the fuel, it needs to take the oxygen into its combustion chamber at extremely high speeds.
  2. Space flight? by spellraiser · · Score: 4, Interesting

    The article starts off with this:

    The space agency's dogged pursuit of extreme speed, officials hope, will ultimately make space flight easier to accomplish.

    OK, so exactly how is this supposed to aid space flight efforts? There is no mention made of that in the article at all.

    I would have thought that the ability to reach incredible speeds in horizontal flight inside the atmosphere is unrelated to both:

    1) Entering orbit (horizontal flight).

    2) Flying in vaccum (different conditions than in atmosphere).

    I'm confused ... any thoughts?

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    1. Re:Space flight? by pe1rxq · · Score: 4, Interesting

      It is important as it might enable more efficient ways to bring stuff into orbit.
      At the moment the only viable way to get stuff in orbit is by strapping a shitload of explosives under it.
      Remember, it is horizontal speed that results in the air pushing a winged body upward towards that vaccum so it is not totally unrelated to space flight.

      Jeroen

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    2. Re:Space flight? by mikerich · · Score: 4, Interesting
      OK, so exactly how is this supposed to aid space flight efforts?
      There is no mention made of that in the article at all.

      Would this be completely unconnected with the Hypersonic Cruise Vehicle (Falcon) concept? DARPA's idea for a global hypersonic bomber that could pre-emptively bomb a country back to stone age before Letterman.

      Still, the Germans beat DARPA to this idea by about 60 years - meet the Sanger Amerika bomber... an aircraft that would fly right around the planet skipping off the atmosphere like a stone thrown across a pond.

      Best wishes,
      Mike.

  3. Complexity not always a good thing by Analogy+Man · · Score: 4, Interesting
    That kind of craft would probably employ multiple propulsion systems including a turbo-jet to reach supersonic speeds, scramjets to take the vessel to the edge of the atmosphere and then chemical rockets to enter the void of space.

    The danger here is that the darn thing will carry all of these systems and have no capacity left over for payload. I recall the Boeing SST back in the late 60's early 70's was based on a swing wing concept. The scale of the mechanical systems to swing the large wing faced them with a difficult choice of a swing wing or passengers...but not both.

    In the physics world one has a sense that they are on to something when the math becomes elegant and simple...I think in the "no moving parts" nature of the scram jet are appealing...a turbofan/scram/rocket combination is not

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  4. Physics Question by Pirogoeth · · Score: 2, Interesting

    I've mostly forgotten almost all my physics, so could someone please answer a question for me?

    Why do you need to be going 25,000 mph to get away from the Earth?

    I can jump into the air and get away from the Earth, for a couple seconds anyway, and I'm not going nearly that fast.

    I thought as you got farther away from a body, the gravitational pull decreases using some inverse-square rule.

    As long as you can get airborne and are able to keep moving upwards, why doesn't it become easier to keep going the higher your altitude?

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    1. Re:Physics Question by eutychus_awakes · · Score: 3, Interesting

      Indeed, all you would need to do to lift a 5-pound object above the Earth's atmosphere would be to supply an engine which can provide 5.1-pounds of thrust for a VERY long time. Trouble is, when you shut the engine off (or ran out of fuel) you would just fall back to Earth unless you somehow managed to achieve orbital trajectory and velocity. You do the math on how much fuel that would take (a lot - more than you could ever possibly carry). Without escape velocity, the Earth has you - forever! It doesn't matter if you travel as far as the Sun - unless you have escape velocity with respect to the Earth, you're going home. Gaining escape velocity with respect to the Sun is another problem. . .

      For the more technically-mided folks out there, the idea is to achieve higher kinetic energy than you currently posess in gravitational potential energy with respect to the Earth. The farther away you go from Earth, the higher your potential energy is (the longer you "fall" to get back to our planet) - so you have to integrate from the surface of the Earth to infinity altitude to determine the total energy you would need to escape the Earth's gravity. The masses cancel each other out - and you're left with approximately 25,000 mph for your escape velocity.

      Be nice to me - I haven't had my coffee yet today.

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    2. Re:Physics Question by Glock27 · · Score: 3, Interesting
      Without escape velocity, the Earth has you - forever! It doesn't matter if you travel as far as the Sun - unless you have escape velocity with respect to the Earth, you're going home. Gaining escape velocity with respect to the Sun is another problem. . .

      Your post was mostly right except for this part. IF (yes that's a big if;) you had sufficient fuel, as you pointed out above, you could fly at 1 MPH to the Moon. And, once you reach the crossover point (where the Moon's gravitational field is stronger than the Earth's), you have escaped in the sense of escape velocity. You won't be going back home.

      Escape velocity is only relevant for ballistic (unpowered) objects.

      Given our current propulsion systems, all of our spacecraft are essentially ballistic except for the new ion powered ones - and those are very low thrust. Practical antimatter propulsion would make things a lot more interesting! :-)

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  5. Circumference by rwiedower · · Score: 4, Interesting

    But if the earth's circumference is around 25,000 miles, and this jet can go 5,000 miles an hour, that would mean it would take only 2.5 hours to get from any location to any other.

    Okay, if it only takes 2.5 hours at top speed to go anywhere on the planet, how much time is spent accelerating and decelerating versus actually flying at Mach 10? And how much fuel are you burning in the process? I remember working at LaRC when they were just starting to test scramjets and I still think the science is good for orbit, but bad for commercial applications.

  6. B-52 Monthership almost as interesting by Bravo_Two_Zero · · Score: 4, Interesting

    Almost as interesting as the X programs is the B-52 mothership that launches them. There was an Air & Space article years ago (no online version at airspacemag.com) about it.

    It's an aging early-model B-52B, evidenced by the non-pointy nose and is 49 years old. There are virtually no spare parts remaining for it, and most of the current inventory (Gs, Hs) don't have any parts commonality.

    Plus, we never sold any of them to other countries, so it's not like there's a stockpile somplace else on the globe. The cost to replace it is prohibitive, given the structural reinforcements needed to carry the craft aloft. Also, the airframe is very young from an hours perspective. In fact, it's the lowest hour B-52 in the inventory.

    The USAF has loaned an H-model to NASA to become the next generation launch platform, but I haven't heard much about it since the 2001 announcement.

    It's a supremely important beast in the research arsenal. And, given our penchant for resurrecting C-64s as web servers and using mame to emulate decades-old cabinet games, it seems like the sort of thing that would interest the average computer geek.

    Like so many things, it's the logistical details of maintaining an archaic aircraft against all odds (and lack of funding) that really become the story rather than the whizz-bang doodad that always gets the front page pictures.

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  7. Re:Why? by lfourrier · · Score: 3, Interesting

    We USED TO be able to go from New York to London in two hours. What the hell went wrong?

    1) US refusing Concorde at supersonic speed over US territory.
    2) Price of petrol
    3) 2 hours of transatlantic flight, 2 hours to go to the initial airport, 2 hours to go from the final airport...
    4) Looking back at this, it was somewhat an ecological catastrophe

    How will all those factors be taken into account by the sdcramjet developers?

  8. Re:Why? by meringuoid · · Score: 2, Interesting
    Mmm... Maybe I can forgive the US banning Concorde overland, given the noise it made; I was in Reading last summer, shortly before Concorde was grounded, and heard one _hell_ of a roar filling the whole place. Looked up and there it was, coming up out of Heathrow. There must have been a hundred rock bands there and nothing came close for sheer decibels. Bloody beautiful, though. Just the shape of it stinks of speed.

    The other killer was probably that it couldn't quite carry the fuel to cross the Pacific. That cut it off from LA - Tokyo, which cut it off from a big moneyspinner...

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  9. My sister did the logo! by TheXerox · · Score: 3, Interesting

    My sister Caity died of cancer at 11 years old a couple years ago..

    Caity was out in California for proton radiation treatment, Joel (uncle in law / NASA engineer) held a party for his Engineering Section at his house and Caity drew a picture of the X43 plane's logo on the sidewalk in chalk.

    After Caity passed Joel took the picture of her sidewalk drawing and went to Nasa to have the plane named in Caity's honor and have her picture on the side of the plane.

    I hope this one does a lot better than the last time, it has a lot of sentimental value!

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  10. Re:Dive? by ValentineMSmith · · Score: 2, Interesting

    While this wasn't actually a "successful" ditching attempt, IIRC, over half the passengers lived through it. The video link on the site doesn't actually lead to a video of the crash, but I can remember seeing the video on one of those "Real-People-In-Real-Pain" TV shows for which the Fox network is so famous. The Aircraft came to rest roughly 500 metres or so from the beach, and the water was relatively shallow. Several people on the beach waded out and helped the passengers to shore.

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  11. Re:Ok, so Jet Propulsion Lab. does space.... by demachina · · Score: 3, Interesting


    http://www.jpl.nasa.gov/about_JPL/jpl101.pdf

    The way this reads is there was a race after sputnik to launch the first U.S. satellite. The JPL/Army Orbiter lost out to the Navy's Vangaurd. Vangaurd exploded on the pad and JPL revived Orbiter but they focused on the satellite more than the rocket. They turned their focus to payloads from them on, and NASA came in to being in 1958 and assumed hegemony over rocket R&D elsewhere. As for not changing the name I assume it was:

    A. Sentimental, since the early JPL had a rich history
    B. To cheap to print new stationary and change signs
    C. Geeks busy doing geek stuff and didn't get around to it

    The original founders are a colorful group. Theodore Von Karman was the leader and guding force.

    Jack Parsons, leading chemist, who was part of an "esoteric order" rumored to be fond of drugs and orgies.

    Tsien Hsue-shen is considered to be the father of the Chinese missile and space program. He was held hostage in the U.S. for a number of years during the red scare when he wanted to return home to China. He was released by Eisenhower as part of prisoner exchanges in Korea.

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