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Post by drewid on Mar 8, 2010 9:37:10 GMT -4
Blackbriar1 seemed to imply that launching the LM into the same orbital plane as the CSM was a problem because the LM landed off target and we didn’t know exactly where it was. Did anybody mention to our friend that the LM and CSM weren't exactly flying blind? That they had two independent ways to determine their relative positions and velocities in addition to ground-based S-band ranging and Doppler for each spacecraft? (That would be the LM's rendezvous radar and the CSM's VHF ranging system.) Unfortunately he bailed out too quickly, and was last seen running south , fingers in ears, singing "LALLALLALLAALAALAAI'mnot listeningggg".
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Post by Jason Thompson on Mar 8, 2010 10:54:33 GMT -4
All of these strike me a made to order, to do one job or a limited type of work, along with the bombe used on enigma and on to guidance stuff on Apollo. The nubbin of my niggles with these claims of pocket calculators or car ECU being more powerful etc. All of these people can say their calculator is more powerful, how many can show it? How many know how a calculator actually works and could work out what Apollo required to do its job? Precisely. A point I have made at least once before (whether here or on BAUT I can't remember) is that my pocket calculator may well have more memory than the Apollo Guidance Computer, but it also uses that memory to perform a wide variety of mathematical functions that have nothing to do with navigating to and from the Moon. It's a question of required functionality, not absolute amounts of memory.
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Post by randombloke on Mar 8, 2010 11:07:57 GMT -4
With reference to calculators being better etc etc (the claim by the OP earlier). I was looking at the Babbage machine the science museum and marveling at its complexity but also what it was aimed at. Working out tables, but only after his death was it shown to work. I'm pretty sure Babbage published his plans in numerous scientific journals of the time and they were generally agreed upon to be functional at the time; several sub-sections were even built (and a couple survive to this day too) and shown to work as expected. Ada Lovelace even wrote a program for it which we now know would have worked had the machine ever been built, so I think it was sufficiently described to know that it would have worked. The problem with it was the technical hurdle of machining all the components to the required tolerances, not the principles behind the mechanism. Oh and getting the people with the money to understand what it was for, which may have been the greater leap considering how much trouble electronic computers had with big businesses in the seventies and how much consternation the Difference Engine caused when it was first demonstrated.
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Jason
Pluto
May all your hits be crits
Posts: 5,579
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Post by Jason on Mar 8, 2010 12:22:54 GMT -4
Laurel, I get that part of practice , practice, but those practices were not done thrusting off a stationary point moving past gravity and attempting to rendezvous or intersect with another vessel moving at what speed? and getting into it`s same plane of orbit, both a vertical and horizontal movement or complex interpolation. As near as I can parse your statement, it's completely wrong. Gemini missions were launched from a stationary point (Earth), moved "past gravity" (through the Earth's gravity), and attempted to rendezvous or intersect with another vessel moving at high velocity, in the same plane of orbit, vertical and horizontal, etc. etc. In fact, the Gemini missions involved larger gravity fields and also had to deal with atmosphere.
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Post by Jason Thompson on Mar 8, 2010 13:07:36 GMT -4
With regard to the Gemini missions, of particular note on the rendezvous side is Gemini 11, which made an m=1 rendezvous with a target Agena. In other words, it shot off the pad and went straight into orbit with and next to the Agena target, without performing catch-up manoeuvres over a few orbits.
And of course Earth orbit speed is 17,500mph, a tad faster than the 3,500mph required to orbit the Moon....
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Post by drewid on Mar 8, 2010 15:36:51 GMT -4
With reference to calculators being better etc etc (the claim by the OP earlier). I was looking at the Babbage machine the science museum and marveling at its complexity but also what it was aimed at. Working out tables, but only after his death was it shown to work. I'm pretty sure Babbage published his plans in numerous scientific journals of the time and they were generally agreed upon to be functional at the time; several sub-sections were even built (and a couple survive to this day too) and shown to work as expected. Ada Lovelace even wrote a program for it which we now know would have worked had the machine ever been built, so I think it was sufficiently described to know that it would have worked. The problem with it was the technical hurdle of machining all the components to the required tolerances, not the principles behind the mechanism. Oh and getting the people with the money to understand what it was for, which may have been the greater leap considering how much trouble electronic computers had with big businesses in the seventies and how much consternation the Difference Engine caused when it was first demonstrated. The other problem with it was that Babbage kept redesiging bits as he went along, sometimes even redoing a second set of drawings as parts were being cast from the first set. The science museum in London has the built the difference engine from the plans, along with the printer, which itself was a comprehensive piece of kit. Now the analytical engine (that was never even started) was a whole different bundle of cogs. Properly programmable via punch cards, with programmable functions in hardware. It could do conditional loops and branches, (Turing complete code), and had a couple of registers and a zero page, and 1000 columns of memory, each column containing 50 integers (so nearly 21kb). It was roughly equivalent to a 6502 chip, except with 50 byte architecture instead of 2byte. Literally 100 years ahead of it's time. What if he'd finished it?
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Bob B.
Bob the Excel Guru?
Posts: 3,072
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Post by Bob B. on Mar 8, 2010 17:07:26 GMT -4
With regard to the Gemini missions, of particular note on the rendezvous side is Gemini 11, which made an m=1 rendezvous with a target Agena. In other words, it shot off the pad and went straight into orbit with and next to the Agena target, without performing catch-up manoeuvres over a few orbits. I was just reading about that last night. Apparently NASA was reluctant to try it earlier because they were concerned with the small size of the launch window. By Gemini 11, however, it was clear that there would be a sizable gap between the end of Gemini and the start of Apollo. If Gemini 11 missed the launch window, they could scrub and reschedule another day. This might delay the Gemini 12 launch, but there was nothing on the schedule after that to interfere with.
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Post by PhantomWolf on Mar 8, 2010 17:24:43 GMT -4
how much consternation the Difference Engine caused when it was first demonstrated. Heh, see my sig....
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Post by Jason Thompson on Mar 8, 2010 18:33:12 GMT -4
NASA was reluctant to try it early because they were concerned with the small size of the launch window. Just because it's quite amazing and very pertinent to the original discussion point of this thread, Gemini 11's launch window for the m=1 rendezvous was 2 seconds. Just to say that again: 2 seconds. So, NASA can fire off a rocket in a 2 second window (determined by the orbit of the target vehicle) through the atmosphere against Earth's gravity, up to 17,500mph, and meet an orbiting object in less than 90 minutes from liftoff, but launching a LM into lunar orbit, with no atmosphere and to a much lower speed, with time in orbit to catch up and rendezvous is too hard?
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Post by dwight on Mar 8, 2010 18:44:53 GMT -4
Yeah well Jason, after reading some quality conspiracy websites I must point out the folly of your argument.
First of all the LAM could never have landed on the moon in the manner claimed by NASA. Everyone knows a rocket/spacecraft must always travel with its "head" facing forward in the direction of travel. There is no way that flimsy LAM could have ever spun on its axis quick enough to land vertically.
Moreso, the technicolor 70mm IMAX video camera, which was mounted right inside the engine bell could never have survived the intense heat of the rocket engine. So not only would the camera be vapourized, but no-one could withstand that heat to remove the video casette either.
Which leads me to the fact that the U-Matic video system could only handle casettes which had 60 minute duration. Someone would have had to swap the casette halfway through the EVA, and after 1 hour we can see both astroMAYBEs right in front of the camera - which wasnt the real camera as that would have been melted - had the LAM landed in the upright position - which we all know it couldnt have.
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Post by fiveonit on Mar 8, 2010 20:32:28 GMT -4
Yeah well Jason, after reading some quality conspiracy websites I must point out the folly of your argument. First of all the LAM could never have landed on the moon in the manner claimed by NASA. Everyone knows a rocket/spacecraft must always travel with its "head" facing forward in the direction of travel. There is no way that flimsy LAM could have ever spun on its axis quick enough to land vertically. Moreso, the technicolor 70mm IMAX video camera, which was mounted right inside the engine bell could never have survived the intense heat of the rocket engine. So not only would the camera be vapourized, but no-one could withstand that heat to remove the video casette either. Which leads me to the fact that the U-Matic video system could only handle casettes which had 60 minute duration. Someone would have had to swap the casette halfway through the EVA, and after 1 hour we can see both astroMAYBEs right in front of the camera - which wasnt the real camera as that would have been melted - had the LAM landed in the upright position - which we all know it couldnt have. Dwight, that's a crock of bull and you know it!! I've been to better HB sites. One clearly shows Neil Armstrong lifting his visor slightly off camera to eat a Ham Sandwich! Now how could Neil be eating a HAM sandwich on the moon??? A Ham sandwich? Everyone knows that he's Jewish!!! NASA must think we're a bunch of Buffoons!!
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Post by ka9q on Mar 8, 2010 20:41:51 GMT -4
Dwight, Dwight...you should know better. Someone will think you're serious...
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Post by gillianren on Mar 8, 2010 20:49:12 GMT -4
So does that mean Buzz and Neil were on the LAM?
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Post by tedward on Mar 9, 2010 4:18:07 GMT -4
I'm pretty sure Babbage published his plans in numerous scientific journals of the time and they were generally agreed upon to be functional at the time; several sub-sections were even built (and a couple survive to this day too) and shown to work as expected. Ada Lovelace even wrote a program for it which we now know would have worked had the machine ever been built, so I think it was sufficiently described to know that it would have worked. The problem with it was the technical hurdle of machining all the components to the required tolerances, not the principles behind the mechanism. Oh and getting the people with the money to understand what it was for, which may have been the greater leap considering how much trouble electronic computers had with big businesses in the seventies and how much consternation the Difference Engine caused when it was first demonstrated. The other problem with it was that Babbage kept redesiging bits as he went along, sometimes even redoing a second set of drawings as parts were being cast from the first set. The science museum in London has the built the difference engine from the plans, along with the printer, which itself was a comprehensive piece of kit. Now the analytical engine (that was never even started) was a whole different bundle of cogs. Properly programmable via punch cards, with programmable functions in hardware. It could do conditional loops and branches, (Turing complete code), and had a couple of registers and a zero page, and 1000 columns of memory, each column containing 50 integers (so nearly 21kb). It was roughly equivalent to a 6502 chip, except with 50 byte architecture instead of 2byte. Literally 100 years ahead of it's time. What if he'd finished it? Yep, twas in London where I saw it. Amazing stuff, thanks for the info there. Superb stuff I think. My reading list has him on it if there is a decent tome but not enough time. Mr Babbage thinks I want to make the log tables more reliable (much thinking and many years later) one behemoth of a machine from someone's thinking.
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Post by tedward on Mar 9, 2010 4:31:01 GMT -4
All of these strike me a made to order, to do one job or a limited type of work, along with the bombe used on enigma and on to guidance stuff on Apollo. The nubbin of my niggles with these claims of pocket calculators or car ECU being more powerful etc. All of these people can say their calculator is more powerful, how many can show it? How many know how a calculator actually works and could work out what Apollo required to do its job? Precisely. A point I have made at least once before (whether here or on BAUT I can't remember) is that my pocket calculator may well have more memory than the Apollo Guidance Computer, but it also uses that memory to perform a wide variety of mathematical functions that have nothing to do with navigating to and from the Moon. It's a question of required functionality, not absolute amounts of memory. So to date it is standoff comments that are vague. Has there been any real attempt from a HB to understand such I wonder? I could argue that my Mac is more powerful than the hand held calculator. If someone had not written the program that I see as the calculator then it would be useless to me for adding and subtracting. and the hand held would be more suited. Indeed, my hand held gets the use on the course I do as it is made for the task, my Mac will not fit in my bag. It will break with all the shaking it would get. Tools built for the job etc. Actually, thinking about it. When I was in school we were not allowed calculators in any exams. But we were allowed slide rules. We had to show working outs obviously but the as I got to grips with this tool prior exams, I could get an answer quicker than my friends in lessons (the few that had well to do parents that could afford theses new fangled dohickeys). We were OK to use them if we could afford them prior exams but still had to show complete working out through the sum to show you knew how to do it. OK, not a good case and probably when they got used to the buttons they would get better but back to "tools for the job". Opps. Rambling.
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