|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Maximum Rate Shuttle Launches
Given a few extra billion dollars, and a year or two for preparation,
what sort of sustainable launch rate could the shuttle attain? -Curious -Charles Talleyrand |
#2
|
|||
|
|||
Maximum Rate Shuttle Launches
On Sun, 10 Jun 2007 18:31:42 -0700, in a place far, far away,
made the phosphor on my monitor glow in such a way as to indicate that: Given a few extra billion dollars, and a year or two for preparation, what sort of sustainable launch rate could the shuttle attain? I don't know hot to answer that question. You'd need a redesign to the point that it couldn't even be called "the shuttle." |
#3
|
|||
|
|||
Maximum Rate Shuttle Launches
|
#4
|
|||
|
|||
Maximum Rate Shuttle Launches
Given a few extra billion dollars, and a year or two for preparation,
what sort of sustainable launch rate could the shuttle attain? Well, let's toss out the money part .... that is looking at the problem backwards. Consider when a shuttle lands, it gets checked out, tweaked, new tank fitted, SRBs stacked. So considering no anomalies this is going to take a month. And with however many we have now, and allowing for some schedule slippage, a launch per month is do-able. (Then you get the invoice.) Considering the operating scrutiny, budget limits, and so on, doing three or four a year is a significant lauch rate. -- Posted via a free Usenet account from http://www.teranews.com |
#5
|
|||
|
|||
Maximum Rate Shuttle Launches
On Jun 10, 11:33 pm, "Revision" wrote:
Given a few extra billion dollars, and a year or two for preparation, what sort of sustainable launch rate could the shuttle attain? Well, let's toss out the money part .... that is looking at the problem backwards. Consider when a shuttle lands, it gets checked out, tweaked, new tank fitted, SRBs stacked. So considering no anomalies this is going to take a month. And with however many we have now, and allowing for some schedule slippage, a launch per month is do-able. (Then you get the invoice.) That seems fine. But are there enough of the specialized machines to build 24 SRBs per year? Can the launch pad support 1 launch per month? Could the tank manufacturer build 12 tanks a year if you have them a year's notice? What's the turn-around time on an orbiter, assuming a willingness to pay lots of overtime, hire and train extra staff, but expecting to suffer a normal amount of normal problems? |
#6
|
|||
|
|||
Maximum Rate Shuttle Launches
Charles Talleyrand wrote:
:On Jun 10, 11:33 pm, "Revision" wrote: : Given a few extra billion dollars, and a year or two for preparation, : what sort of sustainable launch rate could the shuttle attain? : : Well, let's toss out the money part .... that is looking at the problem : backwards. : : Consider when a shuttle lands, it gets checked out, tweaked, new tank : fitted, SRBs stacked. So considering no anomalies this is going to take : a month. And with however many we have now, and allowing for some : schedule slippage, a launch per month is do-able. (Then you get the : invoice.) : : :That seems fine. But are there enough of the specialized machines to :build 24 SRBs per year? Can the launch pad support 1 launch per :month? Could the tank manufacturer build 12 tanks a year if you have :them a year's notice? What's the turn-around time on an orbiter, :assuming a willingness to pay lots of overtime, hire and train extra :staff, but expecting to suffer a normal amount of normal problems? : The original vision called for 40 launches a year (with 5 orbiters, I believe), with an assumption of simple ground operation. In actuality, they'd be hard pressed to manage 8 flights a year (with 4 orbiters). The only way to do better than 8-9 flights a year is use a different vehicle. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
#7
|
|||
|
|||
Maximum Rate Shuttle Launches
In article ,
Fred J. McCall wrote: The original vision called for 40 launches a year (with 5 orbiters, I believe), with an assumption of simple ground operation. They had backed off to 24 with four orbiters by the time of the Challenger accident. In practice, flying 9 flights in 1985 was a strain, and the push to step up the rate further contributed heavily to the accident. In actuality, they'd be hard pressed to manage 8 flights a year (with 4 orbiters). If I recall correctly, the post-Challenger assessment was that there was nothing about the 9/year rate that would have been fundamentally hard to sustain... given greater investment in spare parts, support facilities, and operations manpower, plus some simplifications like actually enforcing the rules about not making late changes in payload manifests. The orbiters weren't the "long pole in the tent" for flight rate, except insofar as shortage of spares made it hard to keep them all operational simultaneously. Note that the post-Challenger flight rate was substantially higher than it is today -- I think it was 8/year when everything went right. The later reductions were for financial reasons, not because there is any deep obstacle to the higher rate. If (dim) memory serves, the fundamental limit set by having only four orbiters was thought to be (in post-Challenger hindsight) something like 15-20/year. That rate would require quite a few more facilities -- e.g., two or three more of the big simulators at JSC -- and a lot of money. You could probably go a bit higher if you first made substantial orbiter changes, e.g. a nontoxic-propellants RCS/OMS system to remove the bottlenecks in the orbiter processing that arise from having to clear the area every time work even comes close to those systems. Building up to even the maximum three-unmodified-orbiters rate *now* would be extremely expensive, and would take several years even with unlimited funding, because a lot of crucial items are long out of production, and it takes time to build new facilities and train new staff. Plus there is that little problem that at such rates, you're probably only a few years from another loss-of-orbiter accident. (One of the more interesting post-Challenger reports -- from OTA? I forget -- concluded that ongoing orbiter production was mandatory for reliable long-term operations, especially if projects like the space station needed a guaranteed minimum fleet size. This was not what people wanted to hear just then, so that report was quietly shelved...) -- spsystems.net is temporarily off the air; | Henry Spencer mail to henry at zoo.utoronto.ca instead. | |
#8
|
|||
|
|||
Maximum Rate Shuttle Launches
On 11 Jun, 07:06, Fred J. McCall wrote:
Charles Talleyrand wrote: :On Jun 10, 11:33 pm, "Revision" wrote: : Given a few extra billion dollars, and a year or two for preparation, : what sort of sustainable launch rate could the shuttle attain? : : Well, let's toss out the money part .... that is looking at the problem : backwards. : : Consider when a shuttle lands, it gets checked out, tweaked, new tank : fitted, SRBs stacked. So considering no anomalies this is going to take : a month. And with however many we have now, and allowing for some : schedule slippage, a launch per month is do-able. (Then you get the : invoice.) : : :That seems fine. But are there enough of the specialized machines to :build 24 SRBs per year? Can the launch pad support 1 launch per :month? Could the tank manufacturer build 12 tanks a year if you have :them a year's notice? What's the turn-around time on an orbiter, :assuming a willingness to pay lots of overtime, hire and train extra :staff, but expecting to suffer a normal amount of normal problems? : The original vision called for 40 launches a year (with 5 orbiters, I believe), with an assumption of simple ground operation. In actuality, they'd be hard pressed to manage 8 flights a year (with 4 orbiters). The only way to do better than 8-9 flights a year is use a different vehicle. All this was deducible during the DESIGN stage. Yet those who were "in the know" promised us cheap access to space. They knew all along that this was poppycock. Can you wonder that we do not believe everything that is trotted out now? - Ian Parker |
#9
|
|||
|
|||
Maximum Rate Shuttle Launches
Today the aged fleet makes it impossible. Just look at the pressure
tanks any one of which can go BOOM at any time Stuff thats old gets all sorts of wierd problems and parts are no longer available, manufacturers out of business. There isnt enough time by 2010 to safely finish ISS. No doubt NASA is signing waivers for lots of bad day creators. ISS will be called complete with our next accident |
#10
|
|||
|
|||
Maximum Rate Shuttle Launches
Ian Parker wrote:
:On 11 Jun, 07:06, Fred J. McCall wrote: : : The original vision called for 40 launches a year (with 5 orbiters, I : believe), with an assumption of simple ground operation. : : In actuality, they'd be hard pressed to manage 8 flights a year (with : 4 orbiters). : : The only way to do better than 8-9 flights a year is use a different : vehicle. : : :All this was deducible during the DESIGN stage. Yet those who were "in :the know" promised us cheap access to space. They knew all along that :this was poppycock. Can you wonder that we do not believe everything :that is trotted out now? : All those people are long retired and probably dead by now, Ian... -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Expendable launches with shuttle installs | [email protected] | Space Shuttle | 5 | July 8th 06 10:40 PM |
shuttle launches on HDNet | ctt | Space Shuttle | 1 | April 5th 06 07:26 PM |
How to Guarantee Maximum Shuttle Safety | bob haller | Space Shuttle | 0 | December 29th 04 01:08 PM |
Shuttle maximum altitude | Mike Miller | Space Shuttle | 18 | November 18th 03 02:01 PM |
Was a second rate FOAM used in the shuttle???? | hank | Space Shuttle | 17 | September 14th 03 02:10 PM |