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In article <[email protected]>, [email protected] (Henry Spencer) writes: |
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> In article <2736@snap> [email protected] (Paul Johnson) writes: |
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>>This bit interests me. How much automatic control is there? Is it |
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>>purely autonomous or is there some degree of ground control? |
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> The "stick-and-rudder man" is always the onboard computer. The computer |
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> normally gets its orders from a stored program, but they can be overridden |
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> from the ground. |
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>>How is |
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>>the transition from aerodynamic flight (if thats what it is) to hover |
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>>accomplished? This is the really new part... |
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> It's also one of the tricky parts. There are four different ideas, and |
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> DC-X will probably end up trying all of them. (This is from talking to |
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> Mitch Burnside Clapp, who's one of the DC-X test pilots, at Making Orbit.) |
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> (1) Pop a drogue chute from the nose, light the engines once the thing |
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> stabilizes base-first. Simple and reliable. Heavy shock loads |
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> on an area of structure that doesn't otherwise carry major loads. |
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> Needs a door in the "hot" part of the structure, a door whose |
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> operation is mission-critical. |
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> (2) Switch off pitch stability -- the DC is aerodynamically unstable at |
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> subsonic speeds -- wait for it to flip, and catch it at 180 |
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> degrees, then light engines. A bit scary. |
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> (3) Light the engines and use thrust vectoring to push the tail around. |
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> Probably the preferred method in the long run. Tricky because |
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> of the fuel-feed plumbing: the fuel will start off in the tops |
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> of the tanks, then slop down to the bottoms during the flip. |
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> Keeping the engines properly fed will be complicated. |
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> (4) Build up speed in a dive, then pull up hard (losing a lot of speed, |
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> this thing's L/D is not that great) until it's headed up and |
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> the vertical velocity drops to zero, at which point it starts |
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> to fall tail-first. Light engines. Also a bit scary, and you |
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> probably don't have enough altitude left to try again. |
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> All work is one man's work. | Henry Spencer @ U of Toronto Zoology |
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> - Kipling | [email protected] utzoo!henry |
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Since the DC-X is to take off horizontal, why not land that way?? |
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Why do the Martian Landing thing.. Or am I missing something.. Don't know to |
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much about DC-X and such.. (overly obvious?). |
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Why not just fall to earth like the russian crafts?? Parachute in then... |
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Michael Adams, [email protected] -- I'm not high, just jacked |
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Please enlighten me... Ignorance is easy to correct. make a mistake and |
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everyone will let you know you messed up.. |
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