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#121
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On Fri, 25 Jun 2004 03:41:16 +0000, Ron Wanttaja wrote:
On Fri, 25 Jun 2004 01:03:41 GMT, Richard Lamb wrote: Hey Ron, help me out some more here on rec.aviation.homebuilt.spacecraft. For the reentry phase from orbit... For the sake of argument (and ignoring the increased fuel required) wouldn't slowing down too much before reentry be a problem? Steeper path, higher G load, and even more reentry heat? 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. But one thing you can't do is "slow fly" a satellite. For any given speed, for any given velocity vector, there is only one possible orbit. Sure, you can probably increase your angle of attack and do a "skip", but that just means that on the other side of the world, you're going to come down at a much steeper angle. Kinda like bouncing a landing without the ability to add a burst of power to catch the bounce. I'm having one of those moments... I had always wondered why you couldn't dolphin in and out of the earth's atmosphere, cooling down in between hops. AC |
#122
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"pacplyer" wrote in message Naa. These people are colonizing space in a much more efficient manner than the government ever could. For the first time manned space is going to be commercially viable. I would think "Colonaut" would be a much better name for them. Cheers "aye" pacplyer I think we saw the last possibility of space colonization for the next century when project Orion was canceled. Someday some one will make it cheap enough but for now it's something to dream about. Tony |
#123
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On Fri, 25 Jun 2004 05:41:36 +0100, anonymous coward
wrote: But one thing you can't do is "slow fly" a satellite. For any given speed, for any given velocity vector, there is only one possible orbit. Sure, you can probably increase your angle of attack and do a "skip", but that just means that on the other side of the world, you're going to come down at a much steeper angle. Kinda like bouncing a landing without the ability to add a burst of power to catch the bounce. I'm having one of those moments... I had always wondered why you couldn't dolphin in and out of the earth's atmosphere, cooling down in between hops. I think you'd re-enter at steeper and steeper angles each time, since you lose velocity at each encounter with the atmosphere. I suspect, at some point, you can't "pull out" and may break up due to the overly steep re-entry. Just a guess, mind you. Ron Wanttaja |
#125
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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 See ya Chuck |
#126
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Charlie Some of the Mars shots used aero braking by dipping into the upper atmosphere of Mars. Some were successful and some not as I remember. Won't go into the why's and where fores but it's possible but may not be practicable. Big John ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ On 24 Jun 2004 01:35:58 GMT, (Regnirps) wrote: (Steve VanSickle) This particular *design* won't work, yes, but why not the "method" (i.e. moving surfaces to make for a "hands off" reentry)? I suppose it can be dome somehow, but you are talking 18,000 mph instead of 3,000. If there is a way to skim along and slowly loose energy I'd love to find it. But as it now stands, as you lose energy you start to drop into more atmosphere and more drag and loose it faster and drop faster and more heat and.... Anyway, an ninformed quick calculation. Kinetic energy is proportional to the square of the velocity. So, 18,000 mph is six times faster than 3,000 mph but you will have 36 times as much kinetic energy, which will become heat (mostly I think). -- Charlie Springer |
#127
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#128
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"Regnirps" wrote in message
... Ron Wanttaja wrote: Another concept was the Dyna-Soar, basically a mini-shuttle from the mid-60s. It was an Air Force project. Don't really have any information on why it was canceled, See opening sequence to any episode of The Six Million Dollar Man. I don't understand- they cancelled Dyna-Soar, took the money from that budget, and used it put Steve Austin back together??? (better, faster, stronger) |
#129
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In article ,
Dillon Pyron wrote: The original design of the shuttle was a lifting body, until they proved to be a bitch to fly. 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? Bernadette |
#130
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On Fri, 25 Jun 2004 09:37:12 -0400, Doc Font
wrote: In article , Dillon Pyron wrote: The original design of the shuttle was a lifting body, until they proved to be a bitch to fly. 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? Bernadette I would guess so (and was thinking the same thing when I made my post). That said, there's little drive to do such a thing. Even though I think it would be much safer than the current design for the ISC "lifeboat". -- dillon When I was a kid, I thought the angel's name was Hark and the horse's name was Bob. |
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