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#131
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You gotta have control power sufficient to deal with the instability, plus
some for maneuvering. The M2-F2 ($6M Man) didn't have it. Fly-by-wire would have done nothing for it; it was just a bad design. The M2-F3 (big center vertical fin) flew much better due to adequate open-loop roll damping and directional stability. That crew return vehicle concept (X-38??) that was/is in the works was basicallly a lifting body design. But that one used a steerable parachute for final approach and landing. Not a bad trade, actually, when you consider the weight cost of something like a deployable control/lift device. This way, the shape can be optimized for controlled re-entry and initial descent. Pete "Doc Font" wrote in message ... So is it feasable at this time considering the advancements in computer controls? Like the F-117 or F-16 are unstable without their computer systems but they work because the computer constantly adjusts the flight. Could they build an easy to fly lifting body now? |
#132
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Ya know, for $6M these days, you'd only get powerpoint slides and promises
of a better/faster/stronger dude. "Jim Carriere" wrote in message ... I don't understand- they cancelled Dyna-Soar, took the money from that budget, and used it put Steve Austin back together??? |
#133
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#134
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Hmmm...... Suborbital global high-speed strike concept? Maybe, maybe not.
wrote in message ... What spinnoffs might come from the X prize venture Good question, I can't think of any. |
#135
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#136
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On Fri, 25 Jun 2004 04:14:25 -0700, ChuckSlusarczyk wrote:
In article , pacplyer says... Yes, I believe you are correct Rich. Was listening to the 104.9 disk jockey that was claiming this was the ten million dollar x-prize attempt. But I believe you are correct on the plan. But if I was Burt: I would have stuck in a couple of sand-filled mannequins and claimed this was attempt #1 since it is so dangerous. pac If he did that he probably would not have made the altitude required. They barely made it as it was due to a minor mechanical glitch.This flight proved the systems and what adjustments must be made. JMHO Has anybody made a guess as to how high spaceship 1 will be able to go when it has passengers + a full rocket engine? AC |
#138
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On Fri, 25 Jun 2004 14:29:02 GMT, "Pete Schaefer"
wrote: Ya know, for $6M these days, you'd only get powerpoint slides and promises of a better/faster/stronger dude. I'll bet AOL spent more than $6M on their ad. "Jim Carriere" wrote in message ... I don't understand- they cancelled Dyna-Soar, took the money from that budget, and used it put Steve Austin back together??? -- dillon When I was a kid, I thought the angel's name was Hark and the horse's name was Bob. |
#139
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Ron Wanttaja wrote:
Like I said on an earlier post, I don't have much background on re-entry physics. But I think it's possible to deorbit going slowly at a fairly shallow angle...you just have to time the deorbit burn properly. Me either, Ron. And I don't think my Holiday Inn Express line is gonna work on this one, either. I thought I'd try to see if I could at least set the problem up. Hey, it's only calculus, right? But I found nothing there I could get hold of except the (obvious) arrogance of ignorance. Humbling... For a body in motion, the first derivative gives the rate of change in position per unit time (i.e.: speed = rate of change of position per second) If the object is accelerating, the second derivative gives the rate at which the first derivative is changing, or the rate of change in speed (acceleration = rate of change in position per second per second). Third derivative gives the rate of change in acceleration (what the physics guys call 'jerk' = rate of change of position per second per second per second). Like the way an old car jerks if there is too sudden a change is how it is accelerating. Quoting Martin Gardner, "Beyond the third, higher order derivatives are seldom needed. This testifies to the fortunate fact that the universe seems to favor simplicity in it's fundamental laws". BUT Simplicity is relative. On orbit, our ship is in steady state unaccellerated motion, right? Well, not exactly. Due to the curved path of the orbit there is an 'outward' centrifugal force that is exactly opposed by the opposite 'inward' centripetal force (of gravity). So our steady state 'unaccelerated' motion is actually a _second_ derivative from the straight line path (ASSUMING the orbit path is perfectly circular?). therefore Adding an acceleration to our _forward_ motion (second and third derivatives) causes an immediate third derivative reaction of the orbital altitude, i.e.: motion inward (if slowing) or outward (if speeding up). If I'm not too badly mistaken, we are up to the SIXTH derivative, and still haven't accounted for any deviation that would result if the acceleration vector is not EXACTLY aligned with the true orbital path in both pitch and yaw. Taking those into account, we are looking at the TWELFTH derivative just to predict what's going to happen when we try to change speed. If we are off in pitch, I think the end result would be an oscillation in the the orbital path. Think about an AC electrical signal imposed on a DC carrier. If we were thrusting straight 'outward', the thrust pushes us to a highe altitude that our orbital velocity will not be able to maintain. As soon as the thrust is removed, and momentum decays, we will drop back down, gaining inward momentum on the way, which will cause an 'undershoot' of our previous altitude, which will again bleed off momentum until we go back 'up', and over shoot again. There is probably going to be a fairly strong damping effect that will eventually (sota) stabilize at the original altitude, but I haven't a clue how to set THAT one up... Sheesh! Rocket Science.... |
#140
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Big John wrote:
Dan True story. Guy in P-51 at low altitude (10K). Opened mask and lit a cigarette. Oxy from mask caused cigarette to flare and burned his face. Made me nervous about the cigars I used to smoke after we got airborne with mask open just hanging by strap. Used the flare gun port on left side of cockpit to get the ashes out of cockpit. Just put cigar down near the hole and flick and poof they were gone. Would be interesting to see the specs on cockpit of SS1. Had to have some pressurization and probably used pressure breathing in conjunction to keep pilot awake/alive. Big John ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~````` On 24 Jun 2004 02:01:07 GMT, (B2431) wrote: Date: 6/23/2004 8:40 PM Central Daylight Time Message-id: Matt My computer bombed so this may go as a dup? I have thousands of hours in jet fighters breathing 100% oxy. We had all kinds of electrical stuff in cockpit(s) and aircraft. High power Radar, Radio's, etc., etc. . Big John ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~ On Wed, 23 Jun 2004 18:28:37 -0400, Matt Whiting wrote: Richard Lamb wrote: In the aftermath of the Apollo 1 fire, NASA took a year (and $75 mil) to redesign the space craft, mature their mental attitudes, and yes, did come back with a much safer vehicle. Yes, but I still wonder how anyone in their right might would use a nearly pure oxygen atmosphere in a vehicle full of humans and electrical equipment... Matt The difference is Apollo 1 was flooded with pure O2 where jet fighters push O2 from a LOX converter to a face mask. Big difference. The only electronics in the mask is a microphone. Having said that the electrical systems in Apollo 1 were poorly routed and protected. It was an accident waiting to happen. Dan. U.S. Air Force, retired Mike was wearing a standard military style oxygen mask, so the cockpit had to be pressurized. But what the cabin altitude was is anybody's guess. Rihcard |
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