Re: Space Access Update #112 9/19/05

On Sat, 01 Oct 2005 17:59:39 -0500, "Paul F. Dietz" <dietz@xxxxxxx>
wrote:

>Josh Hill wrote:
>
>> I've discussed this already. It doesn't seem to me practical with
>> conventional vehicles. The required launch rates are high, the
>> launches are expensive, you have to design, build, and launch the
>> extra docking/refueling apparatus, and there are problems with that 2%
>> failure rate, which starts to look pretty nasty when you're launching
>> several hundred tons in 20K vehicles. IMO, there's a real risk that
>> you'll end up with the Mars mission equivalent of the N1.
>
>
>This argument is defective. It assumes that if one of these launches
>fails, the payload from the other launches must be written off.
>Why can't a replacement launch be made for the failed one?
>You might respond, 'but then you need duplicate hardware'. To which
>I would respond: if you're not building your components in
>quantities of more than one you're not running a serious
>space effort anyway.

Then we aren't running a serious space effort, because we haven't in
general had the capacity to replace a failed payload or even rescue
astronauts quickly.

>Assuming the chance of losing a launch is the same, what launching
>in smaller units does is reduce the *variance* in the amount of
>material lost to launch accidents. Smaller loses are more probable,
>but larger ones much less probable. This should reduce risk
>premiums.

By the time you've built a spare for everything as well as added extra
launch pad and assembly capacity, as well as the ability to quickly
mate a payload in the event of a failure, I doubt that matters very
much.

--
Josh

"It was amazing I won. I was running against peace and prosperity
and incumbency." - George W. Bush
.

Relevant Pages

  • Re: Space Shuttle Grounding....depressing....
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  • Re: Space Access Update #112 9/19/05
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