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#21
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Shuttle program extension?
Pat Flannery wrote:
Derek Lyons wrote: Given that neither Apollo 1 or Challenger was caused by programs being rushed, I fail to see your point. Doubly so since by any rational measurement Orion isn't being rushed either. Apollo 1 was certainly caused by the program being rushed (or "Go Fever" as the astronauts referred to it). Challenger was due to trying to maintain a unrealistic flight rate. Schedule pressure on a single flight, or series of flights, is not the same thing as a program being rushed. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#22
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Shuttle program extension?
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#23
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Shuttle program extension?
Fred J. McCall wrote:
They're called 'fixed costs' because they're FIXED. They don't change no matter what your flight rate is. I think this is an over-simplification. If your ground infrastructure is setup to handle X flights per year and this requires that one shuttle enter maintenance phase before another one is finished, it means that you need 2 maintenance bases, and enough employees to process 2 shuttles concurrently (or even more if a 3rd shuttle is in a heavy maintenance phase monopolising a maintenance bay and employees for months/year) Lower the launch rate to a point where shuttle #1 has fully exited the maiintenance facility by the time shuttle #2 lands, and it means that shuttle#2 can use the same facility and staff that have worked on shuttle #1 just before. In other words, once NASA is given the order to plan for no more than say 3 launches per year for Shuttle, it could then scale its ground infrastucture down. But as long as it has dreams of 12 launches per year, NASA will keep ground infrastructure scaled up to handle the remote possibility of 12 launches per year, even if in reality, it may never do more than 6. So I think there is room to significantly reduce ground costs after assembly complete if NASA is told to not plan for more than 2 or 3 shuttle launches per year allowing it to scale down its ground infrastructure. |
#24
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Shuttle program extension?
John Doe wrote:
:Fred J. McCall wrote: : : They're called 'fixed costs' because they're FIXED. They don't change : no matter what your flight rate is. : : :I think this is an over-simplification. If your ground infrastructure :is setup to handle X flights per year and this requires that one shuttle :enter maintenance phase before another one is finished, it means that :you need 2 maintenance bases, and enough employees to process 2 shuttles :concurrently (or even more if a 3rd shuttle is in a heavy maintenance hase monopolising a maintenance bay and employees for months/year) : If they scale with flight rates then they are not fixed costs. That's not "over-simplification". That's the bloody definition of fixed costs. -- "Ignorance is preferable to error, and he is less remote from the truth who believes nothing than he who believes what is wrong." -- Thomas Jefferson |
#25
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Shuttle program extension?
Fred J. McCall wrote:
If they scale with flight rates then they are not fixed costs. That's not "over-simplification". That's the bloody definition of fixed costs. If they have facilities to support say 12 flights per year, you have fixed costs whether you operate 1 or 12 flights that year. But if you know you won't need more than 3 flights per year, you might be able to scale down those facilities and staffing levels and reduce your fixed costs. (at which point, your costs would be fixed whether you operate 1 or 3 flights per year). Think of it in terms of a factory. If you operate 2 production lines in 3 shifts, your factory will have equipment and employee costs that are fixed whether the factory runs at capacity or below capacity. But if you are only using 1/6th of the maximum capacity, you could shutdown one production line and only hire one shift of employees to produce what is needed and your fixed costs would be much lower. |
#26
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Shuttle program extension?
"John Doe" wrote in message
... Fred J. McCall wrote: If they scale with flight rates then they are not fixed costs. That's not "over-simplification". That's the bloody definition of fixed costs. If they have facilities to support say 12 flights per year, you have fixed costs whether you operate 1 or 12 flights that year. But if you know you won't need more than 3 flights per year, you might be able to scale down those facilities and staffing levels and reduce your fixed costs. (at which point, your costs would be fixed whether you operate 1 or 3 flights per year). Think of it in terms of a factory. If you operate 2 production lines in 3 shifts, your factory will have equipment and employee costs that are fixed whether the factory runs at capacity or below capacity. But if you are only using 1/6th of the maximum capacity, you could shutdown one production line and only hire one shift of employees to produce what is needed and your fixed costs would be much lower. ========================================== From my point of view of being aboard one of those Shuttles when launched, what is happening to the skills and knowhow level of the remaining work crew while this is going on? ?? I recognize great advances in manuals and literature accessibility as computer technology comes in, but I really don't want someone working on my hardwares who hasn't had one of the things apart and reassembled personally at least two or three times, and then tested severely? Someone who hasn't spent *days* looking at fault trees and thinking about what if this or that which isn't there (yet) happens anyway? These staff and physical plant reduction schemes may work ok in a candy factory, but are they really such a safe idea for extremely dynamic machinery such as Shuttles and the like? ?? Titeotwawki -- mha [sci.space.policy 2008 Sep 04] |
#27
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Shuttle program extension?
"Brian Thorn" wrote in message
... On Wed, 03 Sep 2008 20:36:28 GMT, (Derek Lyons) wrote: Schedule pressure on a single flight, or series of flights, is not the same thing as a program being rushed. How many flights does it take until the program is, in fact, rushed? Brian ====================================== The idea of lifting off on a single one of those SRBs came into focus for me when I saw a proposal described here in sci.space.policy, for a three-ton weight on springs (surely with friction dampers too) to absorb and damp the vibration. *Three tons of dumb steel* on a spacecraft? !!? Somebody is spinning like Road Runner up a wrong tree, and no Wiley Coyote in sight. It sounds to me like a severe fault in upper level management. I haven't heard yet why those SRBs vibrate longitudinally in liftoff. Is the burning rate of the solid fuel too pressure sensitive? Titeotwawki -- mha [sci.space.policy 2008 Sep 04] |
#28
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Shuttle program extension?
John Doe wrote:
:Fred J. McCall wrote: : : If they scale with flight rates then they are not fixed costs. That's : not "over-simplification". That's the bloody definition of fixed : costs. : :If they have facilities to support say 12 flights per year, you have :fixed costs whether you operate 1 or 12 flights that year. : :But if you know you won't need more than 3 flights per year, you might :be able to scale down those facilities and staffing levels and reduce :your fixed costs. (at which point, your costs would be fixed whether you perate 1 or 3 flights per year). : :Think of it in terms of a factory. If you operate 2 production lines in :3 shifts, your factory will have equipment and employee costs that are :fixed whether the factory runs at capacity or below capacity. : :But if you are only using 1/6th of the maximum capacity, you could :shutdown one production line and only hire one shift of employees to roduce what is needed and your fixed costs would be much lower. : Go look up the definition of 'fixed cost'. If it varies with level of activity, it is a VARIABLE cost. Let me help you out: Fixed Cost: Fixed costs are operating expenses that are incurred when providing necessities for doing business and have no relation to the volume of production and sales (as opposed to "variable costs"). Examples are rent, property taxes, and interest expense. -- "Ignorance is preferable to error, and he is less remote from the truth who believes nothing than he who believes what is wrong." -- Thomas Jefferson |
#29
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Shuttle program extension?
Perhaps a better way to put it is: the facilities themselves are fixed
costs. They are there whether you use them for 12 flights or 2. The maintenance personnel, replacement parts, etc are all variable costs because you use them only when needed. It's a mix of both. |
#30
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Shuttle program extension?
"Derek Lyons" wrote in message ... "Jeff Findley" wrote: So, just how was the Challenger disaster the fault of the engineers? Have you ever actually studied the Challenger accident as opposed to quoting soundbites? Since when is the official accident report published by an independent team of experts a soundbite? Just what have you been smoking lately? Jeff -- A clever person solves a problem. A wise person avoids it. -- Einstein |
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