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Everything posted by wwwmwww
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I agree with and understand all of that but the last statement. The wait was because of weather, correct. The reason it was a 24-hour wait is because there is only a window of opportunity in the shuttles orbit where it can land at Flordia (or Edwards, or White Sands). If it missed that opportunity say due to bad weather it must wait for the Earth to make a complete revolution below it before that window returns and that revolution takes 24 hours. For example you couldn't land at Flordia if the orbit looked like this. You have to wait till the next time it looks like this (or atleast closer to this). Atleast that is the way it was presented on the news this morning. However my question came from the fact that the orbit passes over Flordia TWICE a day, not just once a day. Something like 9 or 10 hours after the first pass the second pass would look like this. But to my knowledge they've never come in from that direction. Why? Is there a reason they have to come into the atmosphere flying north? Still curious, Carl
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Yes, they landed at Edwards. Carl
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I watched the landing this morning and you guessed it. I've got another question. You guys have been very informative so far so I thought I'd try you again. This relates to the animation that was shown that shows the orbit of the shuttle at 57 degrees in relation to the equator and explained why there was a small window where the shuttle could actually land in Flordia. The Earth is rotating under the orbit and one must wait for Flordia to rotate under the orbit. Actually this is two questions... (1) Am I correct to assume this orbit was significantly different then the last shuttle orbit? From the animations that were shown it sure didn't look like the shuttle would have flown over Texas on the way into Flordia this time. (2) All the landing windows that were shown were from the part of the orbit where the shuttle is gaining latitude (i.e. heading away from the equator). However Flordia would later rotate under the part of the orbit where the shuttle would be losing latitude. They cut the animation just short of this part put you could see it coming. So on Monday when they missed their opportunity why did they have to wait a full 24 hours? From the animation it looked to me as if Flordia would have been crossing the orbit again in something like 8 or 10 hours just that the orbiter would have been traveling south on that part of the orbit instead of north. Was there a reason they wanted to land in the dark or some reason they don't want to enter the atmosphere while traveling south in their orbit? Just curious again, Carl
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Ok... after watching the news this morning I was struck with a second question. It was stated they didn't want to land the shuttle at Edwards this morning partly because if there is a September launch Discovery would have been the Shuttle set aside for a rescue mission if one were needed. This implied that if the Shuttle were to land at Edwards there wouldn't be any chance of a September launch. Why Discovery? We have more then two flyable shuttles don't we? Is there some reason I'm missing that Endeavour couldn't be set aside as the rescue shuttle for Atlantis? I hate it when the obvious questions go unanswered. Just curious, Carl
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I certainly agree on all points. Its a big step and it's certainly a step in the right direction. However it's also just one step of many that will be needed. I can't wait to see Rutan's next step. Carl
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If I recall correctly ALL Shuttle missions have gone WITH the rotation of the Earth. Its a "free" boost at list off and lets you get to orbit with less energy. However on re-entry the Shuttle is going so fast that you are going to be coming into a head wind regardless. I certainly don't believe there are any Mach 20+ winds in the upper atmosphere. I certainly can't imagine the Shuttle entering the atmosphere and having a tail wind push her back up into orbit. Yes, but you need ALL that forward momentum to STAY in orbit. If all of it were converted to upward momentum you'd go strait up till all of it was converted to potential energy and after that you'd FALL straid back down again. And I'm quite sure that climb and fall would take less then 90 minutes. See above... the Shuttle would come down into a head wind regardless of the direction of its orbit. The re-entry problem would be no different if the Earth wasn't rotating at all. I'm quite sure the Shuttle doesn't have enough energy on board to break orbit and I'm also quite sure nothing in the upper atmosphere would be able to give it that much energy. Carl
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My thinking is this... and granted I'm not 100% sure its sound... The space shuttle is in a near circular orbit. It slows down for re-entry and now it's in a lower orbit that intersects the atmosphere. It hits the atmosphere and loses more energy and say it skips. Since it's lost energy it sould be in a still lower orbit and the one it was in before intersected the atmosphere so this new one should too. At orbital speed it takes about 90 minutes to complete the entire orbit. So that said I don't see a way to avoid a second re-entry attempt in that amout of time. If it lost alot of energy on the first skip that time would be even less. Once the shuttle's orbit intersects the atmosphere the shuttle is coming down one way or the other unless it fires it's rockets to add more energy into the system. I just don't see the atmosphere adding energy to the shuttle. The exception I could see to the above is if the orbit the shuttle put itself on for the first attempt at re-entry were highly eliptical. Then maybe it could end up in a more circular orbit after a skip which had a lower total energy but was maybe still just above the atmosphere. I however think that's very unlikely as the shuttle's altitude is low enough that ANY orbit has to be nearly circular. A highly eliptical orbit with the energy the shuttle has would take it inside the planet. Carl
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See my last post. Eventually I believe is less then 90 minutes. They aren't going to starve or freeze in that time. Carl
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The Shuttle orbits the Earth about every 90 minutes I think. If the Shuttle lost enough energy to attempt re-entry and "skipped" off the atmosphere I don't see any mechanism for them to put themsleves into any other orbit that wouldn't intersect the atmosphere in at most 90 minutes. That is unless they fired some more rockets on the Shuttle. I don't believe any maneuvering would be required. I think they'd be trying another re-entry within 90 minutes regardless of rather they wanted to or not Again I think the shuttle should SLOW down each time it raised away from the atmosphere. See my last post. However I think the real problem is the heat. Yes the tiles would heat up a little bit each time and being that high up they wouldn't be able to dissipate much heat into the atmosphere. They'd only be able to lose heat radiatively. If they are gaining heat fasther then they are losing heat for a long enough period of time you have a problem. Carl
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You are correct of course. My bad. However was that orbit an orbit about Earth or an orbit about the Earth/Moon system? That's the first I've read anything about the atmosphere actually adding energy to the shuttle. I thought the friction with the atmosphere would result in kinetic energy being turned into heat and dissipated. Though most of that heat might just end up getting stored in the tiles at that altitude. Can you point me to an article on this trampline effect? This just doesn't sound quite right to me. Its possible to gain altitute without gaining any net energy. Through a rock up into the air. After it leaves your hand it has nothing left to give it energy yet it still continues to go up. It's turning kinetic energy into potential energy while the net energy stays the same. Actually its losing enegry due to friction the whole time. I think the shuttle would be doing the same thing. It would just be turning its forward kinetic energy into potential energy while it was gaining altitue. I don't believe it's accelerating... I think its decelerating. Carl
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Ok... just read it. This figure: is very misleading. It implues you are nearly going strait down when you hit the upper limits of the atmosphere. That's incorrect, the first figure is much better. This sentence "This feature is true in the case of the Space Shuttle, the only vehicle that currently uses a glide entry trajectory." is also incorrect. There was also the Energia-Buran Reusable Space System unless it's not considered "current". And for an article about craft re-entering from a circular orbit these sentences are completely wrong "If the entry angle is too shallow, the vehicle will generate too little drag and not slow down enough to be captured by the Earth's gravity. The craft will instead skip out of the atmosphere and back into space with insufficient fuel to return to Earth again." 1. The craft is ALREADY captured by Earth's gravity. Where does the energy to escape this come from? 2. This might be true of a craft entering the atmosphere that isn't already in orbit but even in that case the angle of attack is independent of the fuel on board. There is NO need to tie those two together. To me the only useful sentence there is this one "A vehicle using a skip trajectory can travel much farther downrange than either the ballistic or glide options allow, but the primary disadvantage is much higher aerodynamic heating." but even there it doesn't go into why. One would think that if you slow down slower you would generate less heat. Happy now? Carl
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I really enjoyed watching the SpaceShipOne flights so PLEASE don't take this as me knocking that effort. It was a great accomplishment but it's very hard for me to see this craft or anything like it taking people to a hotel in orbit for example. To get to orbit you need more then just altitude. You need the lateral speed to stay in orbit or as soon as you shut off your engines you fall back to the Earth. That's just what SpaceShipOne did. The speed required to get the altitude is actually a very small part of the puzzle. You could probably get up there and back down again while never going over Mach 2. However to stay in orbit you need a speed of something like Mach 25. Burt Rutan is still an order of magniture away from being able to offer much more then a short joy ride at the moment. It's certainly a good step in the right direction but he's got a long way to go yet. If you were to carry SpaceShipOne to orbit in the Shuttle for example and were to let it then try that reentry maneuver on it's own I dare say the pieces that would make it back to Earth would probably be look worse then what was left of Columbia. Carl
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Correct me if I'm wrong but wasn't there talk from Nasa back at the time of the Columbia disaster that if they had known about the damage to the tiles they could have tried to came in at a shallower angle of re-entry? As I remember it, it was stated that it would have taken it easier on the damaged areas but since the overall re-entry would have taken longer the stuttle would have been exposed to the high temperatures for much longer and that could have damaged Columbia in other areas to the point she'd never be able to fly again. Also I don't believe the Shuttle can "skip off into the Big Black". The shuttle is in orbit (unlike the Apollo capsule on the way back from the Moon). Any contact with the atmosphere will cause the shuttle to slow down. If the angle is too shallow it might skip but it will have lost energy and it will come back down and make contact with the atmosphere again as it no longer has the energy to stay in orbit. Think of a rock skipping across a pond. That said I'm no so sure a few skips before re-entry are bad thing. I'd tend to think any why of lossing that enegry as slowly as possible would be a good thing however I'm certainly not an expert in this area. The other part of this is the tiles only slow the transfer of heat. If one side of them were held at the heat of re-entry for long enough the other side would eventually get to that temperature too unless something was actively cooling it. I think that plays a roll in determining just how shallow an angle of re-entry can be used for the shuttle. Carl
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I'm not sure it's that simple. Disregard fuel, economics, and payload assume you did have enough thrust to slow from Mach 25 to 0 onboard. As soon as you start to slow down you start to fall out of orbit. I think the shuttle would hit the atmosphere anyways well before it lost all it's orbital speed. Also keep it mind that while you are falling out of orbit you are accelerating in the downward direction due to gravity. If you were far enough above the atmosphere such that you could lose all your orbital speed you'd still be falling strait down with alot of speed when you did hit the atmosphere. Maybe if you had twice as much thrust needed to come to a stop on board you could direct half of it in a forward direction till you lost all your orbital speed and used the other half directed down to control your descent rate. It'd probably take you twice as much fuel to get down as it did to get up though. The part I'm not as clear on is this. Yes you have to convert all the momentum to heat in the atmosphere to slow down and loose that enegry before you touch down but I'm not sure how much leeway they have in just how slowly they go about slowing down. I think they can take the whole process much slower and maybe not generate near as much heat however I think the problem becames that if you take it too slowly there is heat applied to the tiles for long enough that the heat can eventually make it through the tiles themselves even though the actual heat on the outside surface is much less. If you were to actively cool the inner surface of the tiles maybe you could come in real slow and take a day to dissipate all that energy. Just a thought, Carl
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I probably shouldn't touch this but... (famous last words, right?) Anyways, I talked to him several times on the phone (never meet him in person) and I always found him very helpful. He provided the whole history of the NewType Legioss&Tread to me. How it was made from the same master as the MonoCraft kit etc. He was also very open about the 1:48 scale kits and how he got them. In short he seemed nice enough to me and I bought several kits from him and never had a problem there either. He does seem to have hit quite a few of you the wrong way though and I'm not sure why. If his shop was still open I'd probably ask you to PM me as I had sent several people his direction with regards to the Legioss&Tread kit and as far as I know none of them came back to me saying they had problems. With the store gone I guess it's a mute point. Just wanted to say that, Carl
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Still have a catalog or two myself. There resin kit of the Beta/Tread and Alpha/Legioss was what lead me to them. They also had several of the 1:48 Club-M kits at GREAT prices considering they were event only kits. Carl
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WOW!!! Great minds think alike. Thanks for all the info everyone, Carl
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Hello, After watching all the news coverage this week of the issues with foam falling off the shuttles exterior fuel tank and seeing so many people eager to jump up and call it a design flaw, a question popped into my head that I'd LOVE to see asked. However I'm not sure were this question should best be directed so I thought I'd bounce it off a few of the aviation experts here to see if they thought I was on to something. First let me say that I have a Ph.D. in Physics and I've been a process engineer in the semicomductor industry for almost a decade. I can't count the number of times I've seen this scenario: 1) Engineer_A/Designer_A creates something that works and has all his checks and balances in place. He knows his part/design/process better then anyone else is ever going to. 2) Engineer_A/Designer_A retires, is laid off, fired, or for some other reason replaced with Engineer_B/Designer_B. 3) Engineer_B/Designer_B under heavy pressure to cut costs removes a check put in place by Engineer_A/Designer_A that he doesn't fully understand the reason for and creates a very big mess. I've seen the above scenario play out over and over again. It usually is the result of management trying to save a few dollars and more often then not it costs them millions. Anyways with that in mind who here remembers that the external fuel tank used to be painted white? I even remember the claim being made that the reason they stopped painting it was two fold. One it saved them the cost of the paint and the labor needed to apply it. Two it reduced the weight of the tank by the weight of the paint that used to be applied. The number 40 pounds rings a bell in my head but I'm not sure I trust that memory. So the question that's playing over and over in my head... did anyone stop to ask WHY they painted it in the first place before they asked how much money they could save by not painting it? Is it possible that who ever designed it wanted some special paint applied over the foam specifically for the reason of keeping the foam from falling off during a launch? Part of me tells me I have to be out in left field as I have NO access to NASA and surely the brains at NASA would have found the problem in 2 and a half years had it been that simple. But the other part of me knows that 9 times out of 10 its the very simple/obvious things that get over looked. Anyone here have any REAL info or experience in this area? If I'm on to something any idea how to get this thought to someone at NASA that might actually be able to act on it? I've always been a big fan of the space program and personally I'm hoping the Space Shuttle has many safe flights left in her. Thanks... just couldn't sleep tonight till I got that off my chest, Carl
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Yes, they are however I don't really have the site organized. My HTML knowledge is very limited. So far I'm basically just uploading stuff and sharing it here or at: http://www.tron-sector.com or http://news.povray.org/groups/ The biggest organized collection at the moment is here: Tron Sectors Fan Art Page for me However that's not everything. If there is something you remember that you don't see there let me know and I'll be happy to post it here. Carl
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This is the path of the fly-by: The animation is here: http://www.wwwmwww.com/TRON/900kbs.avi All comments welcome, Carl
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4chan is back, and the mecha section is awesome!
wwwmwww replied to Pat S's topic in Anime or Science Fiction
More or less yes. The booster you see in the lower right is an early version of the Tread (aka Beta). I've also seen another preproduction Tread that is different from both this one and the one they ended up using too. However I'd be very hard pressed to find that picture now. Let me look around and see what I can find. Carl -
4chan is back, and the mecha section is awesome!
wwwmwww replied to Pat S's topic in Anime or Science Fiction
I've seen those before. Not sure where though at the moment. I think Shawn scanned them for me from one of his books years ago. Carl -
Finished watching Macross 0 yesterday. WOW!!! The visuals were breath taking. The plot left me with a few questions though. Can someone point me to the appropriate thread where they should be asked? More on topic. It was nice seeing the new monster even if they waited till the last few minutes of the last episode to show. Looks like the hands are primarially used to anchor it before the main guns are fired. Carl
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Very very cool. I love it. Keep up the great work. I can't wait to see more. Carl
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Please help support this cause. I'm 198 on the list. Thanks, Carl