Why are the Shuttle Boosters the size they are.
This is interesting. :rolleyes:
I got this from my Little Brother who is in the Air Force. INTERESTING HISTORY LESSON Railroad tracks. This is fascinating. The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number. Why was that gauge used? Well, because that's the way they built them in England , and English engineers designed the first USrailroads. Why did the English build them like that? Because the first rail lines were built by the same people who built the wagon tramways, and that's the gauge they used. So, why did 'they' use that gauge then? Because the people who built the tramways used the same jigs and tools that they had used for building wagons, which used that same wheel spacing. Why did the wagons have that particular odd wheel spacing? Well, if they tried to use any other spacing, the wagon wheels would break more often on some of the old, long distance roads in England. You see, that's the spacing of the wheel ruts. So who built those old rutted roads? Imperial Rome built the first long distance roads in Europe (including England ) for their legions. Those roads have been used ever since. And the ruts in the roads? Roman war chariots formed the initial ruts, which everyone else had to match or run the risk of destroying their wagon wheels. Since the chariots were made for Imperial Rome, they were all alike in the matter of wheel spac ing. Therefore the United States standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot.. Bureaucracies live forever. So the next time you are handed a specification/procedure/process and wonder 'What horse's ass came up with this?', you may be exactly right. Imperial Roman army chariots were made just wide enough to accommodate the rear ends of two war horses. (Two horses' asses.) Now, the twist to the story: When you see a Space Shuttle sitting on its launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are solid rocket boosters, or SRBs. The SRBs are made by Thiokol at their factory in Utah . The engineers who designed the SRBs would have preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site. The railroad line from the factory happens to run through a tunnel in the mountains, and the SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track, and the railroad track, as you now know, is about as wide as two horses' behinds. So, a major Space Shuttle design feature of what is arguably the world's most advanced transportation system was determined over two thousand years ago by the width of a horse's ass. And you thought being a horse's ass wasn't important? Ancient horse's asses control almosteverything...and CURRENT Horses Asses are controlling everything else. |
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Well, I knew about the war chariot/track guage relationship, but not the SRB thing. I've learned something today, and all this time I've believed my mind was too full to hold another fact!
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http://www.snopes.com/history/american/gauge.asp
http://www.snopes.com/history/american/gauge.asp http://www.snopes.com/history/american/gauge.asp Quote:
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Did I forget to mention the following?
http://www.snopes.com/history/american/gauge.asp Don't forget: almost everything 'forwarded' to you from a long list of others is an urban legend or an intentional attempt to get you to forward it to everyone in your address book to help bog down e-mail systems. |
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I never claimed it was a "true fact". I just thought it was funny. |
Fred - I take it you didn't care much for the old TV show called "Connections" that used to be on Discovery or TLC. :)
Even the Snopes article from the link you posted indicates there is some basis in truth for some of the "connections" albeit loose ones. ... Bill |
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I've never heard of it. Must be from a long time ago. No time to Google it. |
Connections.... now THAT is a series that would be cool to see on DVD. Wonderful stuff.
I agree with Bill that the tone of the Snopes article was more of a "it could be true" - except for the bit about the tunnel constraining Thiokol's shipping - than a "not true". I guess that's what the Mythbusters would call a "plausible". |
What I really want to know is why notebook paper is 8-1/2 x 11 inches? Where did THAT standard come from?
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Just like the number of licks to get to the center of a Tootsie pop, the world may never know. From Wikipedia: Quote:
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And the SRBs wouldn't need to conform to rail car limitation if a certain senator from Utah hadn't placed himself in the way of the space shuttle budget approval and insisted that the SRBs be built in Utah. The original plan was to build them in (IIRC) Louisana and barge them over to Kennedy SFC.
This would have results in much longer sections and many fewer SRB sections and therefore fewer joints and therefore fewer of the infamous O'rings. Arguably, that senator's greed killed the Challenger crew. I think he's also one who bummed a ride when they were launching politicians. Too bad they didn't leave him up there. |
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I'm sure Fred will tell us. :rolleyes: Or if sombody else does he'll correct them. ;) |
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Well, there was SOME justification for the decision to cast the propellant in Utah-- the cool dry climate there, especially the low humidity, helped considerably in getting a CONSISTENT propellant casting, especially in casting multiple segments for a solid rocket motor. Aerojet had created the world's largest solid rocket motor, a 260 inch behemoth which was static tested as a possible (cheap? or so the thinking went) replacement for the Saturn IB first stage (cluster's last stand) instead of the nine clustered tanks, thrust structure, and eight clustered liquid engines used on that stage. The cast it in Florida (IIRC) because the 22 foot diameter and massive weight precluded moving it very far if at all. They test fired it in a 'silo' test stand (which is there to this day, but abandoned) and there were some difficulties encountered with the casting of the grains and the motor itself which were basically 'traced back' to variable temperature and humidity messing up the pours. The engine didn't perform as expected, and basically broke the test stand from the vibration, etc. so they abandoned the idea. A few years later when shuttle decided to go with solid rocket boosters, Morton Thiokol, who had extensive experience with solid rockets from their ballistic missile work for Air Force, won the contract. Their facilities were in Utah, and really sold the idea that their products (large ICBM solid rocket motors for missiles like Minuteman) had given them considerable experience in this area, and they wouldn't have the problems casting the much-larger shuttle SRB segments because the dry climate in Utah made casting pours more consistent and easier. BUT, because of the weight of the fully-fuelled segments, the only realistic way to transport them was by rail-- they would be too heavy and too big for road transport, and MUCH too heavy for air transport, and Utah doesn't have any water shipping ports capable of shipping them by barge. This meant that the SRB's were ultimately limited in diameter, which of course in a core-burning solid rocket, determines the burn duration (more or less). This is one reason why the Ares I is running into problems now-- increasing the thrust is fairly easy, adding another segment or so to give it more 'kick' off the pad, but the short burn duration of about two minutes, coupled with the enormous initial weight of the solid rockets, which must be moved FULLY FUELLED to the launch pad, unlike liquid rockets which are moved dry and therefore VERY light (in comparison) means that basically the first stage can't do enough of the work of getting the upperstage to a speed and altitude that would be more advantageous performance-wise in the ascent profile. Essentially, the vehicle stages a little too early, throwing more work onto the second stage, which then has to get bigger to compensate, which then requires more thrust, like a 500,000 lb thrust SSME, which unfortunately can't be airstarted on a second stage, requiring the use of a J2-X with around 290,000 lbs thrust (IIRC) which really is a bit too low a thrust level for such a heavy stage. This causes a lot of difficulties in getting the stage masses and velocities and trajectories optimized and limits performance. IF the SRB's could be made larger in DIAMETER, then the burn duration would be increased allowing for the first stage to do more work on the ascent, which would allow the upper stage to be properly sized for it's J2-X engine, getting more performance out of the entire system. Unfortunately that would have two problems-- 1) the SRB's would be too large for rail transport (tunnels and bridges are too low/small) and 2) entirely new SRB casings would have to be fabricated, or the SRB's would have to be switched to expendable filament wound casings like solid rocket nuclear missiles use. The size problem COULD be worked around by building a whole new factory for solid rocket motor production either along the TX or Louisiana coast somewhere, allowing shipment through the Intercoastal Waterway by barge to Florida, just like the S-IC stages and External Tanks built at Michoud, but such a factory would have to be built FROM SCRATCH and probably air conditioned to maintain humidity and temperatures at controlled levels for reliable consistent propellant pours; such a facility would be ENORMOUSLY expensive. OF course changing the diameter and casings would essentially be building an entirely new solid rocket motor, again being ENORMOUSLY expensive, so NEITHER is going to happen. Also, it would take jobs out of Utah, which would get the politicians there lobbying HARD against any such proposals. So, these things are kinda circular, and decisions made decades (even centuries) ago still have consequences on how we do things today, usually on many levels... Later! OL JR :) |
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I once verified 122 licks to get to the center of an orange Tootsie Pop. I achieved this in the summer of 1979 after 60 consecutive days under the arctic ice. The books, magazines, and movies just weren't keeping me focused any longer. Jeff |
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So was this on a boomer or fast attack? Also, an early happy BD. I was born the same day. :) Greg |
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http://www.youtube.com/watch?v=LZ0epRjfGLw |
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From the Tootsie site http://www.tootsie.com/gal_machine.php |
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Yes, I saw that (I looked at Amazon right after I posted before). Not "was" but "is". Mr. Burke is still with us. One of the things Amazon has is an Apollo 11 prgram from the BBC co-hosted by James Burke (apparently aired in 2006 originally). It, as well as all the discs from the first Connections series are now near the top in the family Netflix queue :)! |
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Fast attack. USS Flying Fish SSN 673. My watch and battle station was in the SONAR room. Thanks for the early Happy BD! Jeff |
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That was a fabulous show! |
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