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Post by LunarOrbit on Aug 3, 2005 14:58:06 GMT -4
Think of it like a race track... lower orbits have a shorter path around the Earth than higher orbits. That means an object in a low orbit can cover more distance in the same amount of time. In track & field races they stagger the starting positions to compensate for this so that the runner in the inside track won't have an advantage.
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Post by skinbath on Aug 3, 2005 15:03:28 GMT -4
Actually it's due to orbital mechanics. In a lower orbit your speed increases, therefore you "catch up" to the object in a higher orbit, which is travelling slower. I guess I`ve some reading to do, I don`t know when though; This is a long term project! ;)There`s so much to read!
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Post by ottawan on Aug 3, 2005 15:05:38 GMT -4
That's the challenging thing about learning! You have to work at it I've been doing that for 50 some years now and I'm still learning.
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Aug 3, 2005 15:30:05 GMT -4
Let’s say you’re in the same orbit as your target vehicle but it’s a few hundred miles ahead of you. We’ll assume your orbital period is 90 minutes and you’re lagging behind the target vehicle by two minutes. If you can decrease your orbital period to 88 minutes, then after on complete orbit you will have caught up with the target. What you have to do is decrease the radius of your orbit enough that your new period is 88 minutes. You do this by slowing down. Slowing down will cause you to start falling toward the Earth and speeding up in the process. You will pass underneath the target vehicle and move ahead of it by a few hundred miles by the time you’ve completed 1/2 orbit. At this point your altitude will start to increase and you’ll begin slowing down. By the time you’ve completed the next 1/2 orbit you’ll be back to your starting point 88 minutes after you began. However this time the target vehicle will be at the same place. I guess I`ve some reading to do. I don`t know when though;This is a long term project! ;)There`s so much to read. My Orbital Mechanics page might have more math than you want but its a possible starting place: www.braeunig.us/space/orbmech.htmI've been teaching myself about this stuff a little at a time for about ten years. It's just a hobby so there's no great rush; I do what I can when I can.
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Post by skinbath on Aug 3, 2005 15:34:35 GMT -4
Cheers you guys; the above explanations have helped.
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Post by sts60 on Aug 3, 2005 16:15:42 GMT -4
sts60 wrote earlier: This doesn't hold for laymen looking at something out of their experience. Orbital mechanics is an example. Why the heck would you slow down to catch up with something flying ahead of you? That "looks wrong!"
I`d appreciate you taking the time to explain this, Sure. "What they said."
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Post by JayUtah on Aug 3, 2005 16:27:20 GMT -4
No- as engineers say, "If it looks wrong, it probably is wrong.
Engineers most certainly do not say that. A major part of our training is in relying upon objective and defensible rationales specifically in contrast to hasty or subjective judgments.
So are you willing to discuss the technical particulars of why the LM is supposedly unflightworthy? Or are you going to continue to believe that a part-time Tennessee video cameraman knows more about space engineering than space engineers?
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Post by Mr Gorsky on Aug 4, 2005 4:44:23 GMT -4
What has always irritated me about this argument that the LM doesn't look capable of landing on the moon, is that it is actually a very strong argument in favour of it doing just that.
If NASA were going to pull a hoax that would fool the layman, they would make the LM look more convincing to those coming at it from that perspective.
However, the experts would then be suspicious. So to fool them NASA would have to make the LM conform to the experts' expectation of how a vehicle designed solely for use in space would look - and you would likely end up with something that looked like the LM.
So, you are left with two possibilities ...
Either the LM is a fraud and never landed on the moon, but was put together in such a way as to convince the experts that it could, and did. That would be the only way to have any chance of making a hoax work.
Or, the LM was put together in the best way to accomplish a specific task (landing on the moon) and fulfilled that task exactly as advertised.
Either way, the fact that it might "look wrong" to a layman is completely and utterly irrelevant.
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Post by PhantomWolf on Aug 4, 2005 11:12:46 GMT -4
I always find it funny because they look at the outside reflective layers that are just thermal and micrometeor shielding and had nothing to do with how space worthy it was. Because it operated entirely in a vacuum the outer layers didn't need to be stuck on tightly. None, not one of them, nada, zip, zilch, zero of the anti-LM claims show the interior pressure hull of the LM and make a claim that it wasn't capable of what it did.
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Post by JayUtah on Aug 4, 2005 12:57:25 GMT -4
Even those who see the internal structure are sometimes convinced it is too flimsy. The magic of the LM was structural efficiency: roughly the ratio of dead load to strength. A thick beam is very strong, but it is also heavy and imposes a dead load of its own. A truss is also very strong, but it is very light. The truss is more structurally efficient than the beam.
If you try to guage the LM's strength from an informal visual assessment of its bulk -- even the bulk of the structural elements -- you're going to get it wrong. This is exactly why engineers do not tell each other to trust informal visual inspections. Engineering is about testing the strength, or if that's not possible, computing the strength. It's certainly not about guessing at the strength by looking at photographs of it and scratching one's chin.
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Post by PhantomWolf on Aug 4, 2005 13:10:40 GMT -4
Just out of curiousity, margamatix, since you don't think that the LM looked like it would work. What, in your opinion, would a Lander that would work actually look like?
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Post by sts60 on Aug 4, 2005 13:44:01 GMT -4
That's a pretty good question.
A lot of people get their impression of what spaceships should look and act like from Hollywood, which tends to show "spaceships" built like industrial refineries, only more massive and with big honkin' rockets.
Of course, as Mr. Gorsky was discussing, the claim that an LM was obviously too flimsy to do the job doesn't make much sense even without considering the engineering. NASA built something that this small number of laymen could see through without any effort? What kind of ultra-expensive, murderously efficient, nearly omnipotent hoax is this, anyway?
I suppose I could come up with another scenario: NASA built "gritty realism" into the hoax. That would make more sense to me than a sleek fake.
The problem is still that judging the LM by a superficial look is simply inadequate. But then again, so are the HB arguments which go beyond that. They are all based on mistakes of fact and ignorance or avoidance of actual engineering principles.
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