Re: Back to the Moon

On Tue, 20 Sep 2005 20:45:23 -0500, "w.d.greene" <bil64@xxxxxxxxxxx>
wrote:

>
>"Josh Hill" wrote:
>> "w.d.greene" wrote:
>>
>>>For those m.w. folks who are fans of NASA:
>>>
>>>http://www.spaceref.com/news/viewpr.html?pid=17836
>>>
>>>Finally today was the official roll out of the plan. You probably already
>>>heard about this on the news, but if not, here you go.
>>>
>>>Bits and pieces have been floating around in the press prior to today, but
>>>it's good to be able to openly point to something and say, "See, I'm
>>>working
>>>on that thing right there."
>>>
>>>First flight of the Crew Launch Vehicle should be in 2012. First lunar
>>>mission should be in 2018.
>>
>> OK, here's a question for you:
>>
>> "NASA's Crew Exploration Vehicle is expected to cost $5.5 billion to
>> develop, according to government and industry sources, and the Crew
>> Launch Vehicle another $4.5 billion. The heavy-lift launcher, which
>> would be capable of lofting 125 metric tons of payload, is expected to
>> cost more than $5 billion but less than $10 billion to develop,
>> according to these sources."
>>
>> I can see the need for a new CEV, but I thought the idea of reusing
>> shuttle components was to reduce the cost of developing a new vehicle.
>> Why wouldn't it be cheaper to retrofit existing designs, e.g., use the
>> Delta IV heavy to launch the CEV and an upgraded Saturn 5 as the heavy
>> lift vehicle?
>
>Good question. The option of pursuing upgraded, heavy-lift versions either
>the Delta IV and the Altas V was in the trade space. Launch solutions for
>these options were drawn up and dutifully considered. I believe that the
>reason that these were not chosen was because they could not provide a clear
>pathway towards missions beyond short-term lunar sorties. In other words,
>they'd be difficult to evolve into something that could be used for the
>construction of a lunar base or for the pursuit of a Mars mission. The idea
>here is to put into motion an evolveable architecture for the next thirty or
>forty years of space exploration. That is why the center piece for the
>lunar missions is a monster heavy-lift vehicle on par with the Saturn V.
>
>Other issues also exist with the notion of using Delta IV or Atlas V as a
>crew launcher. First of all, neither is human rated. The process of
>bringing these vehicles up to modern human-rated standards would be nearly
>tantamount to redesigning these vehicles from the ground up. Sure, it's
>possible and it's something that's been examined extensively over the last
>couple of years. Basically it's been examined enough to understand that it
>isn't a cheap alternative. On the other hand, all of the legacy Shuttle
>hardware is indeed designed to be and certified as human rated.
>
>The option of resurrecting the Saturn V is not really a viable option.
>Quite simply, the piece parts and the infrastructure just don't exist
>anymore. It would be more difficult, in my opinion, to attempt to recreate
>the Saturn V than to build its Shuttle-derived equivalent, which is
>essentially what we plan to do.
>
>Note that I'm not saying that what's been revealed is not the only plausible
>choice. There were other options on the table that I thought to be have
>some advantages over the final choice. But this is what we have and, if
>given the resources and the time, I'm confident that we'll successfully pull
>it off.
>
>Hope that helps.

Thanks, it's an excellent rundown.

I understand the need for the HLV, and never questioned the need for
developing it if it wasn't more economical to start with the Saturn.
But I'm still having trouble with is the $4.5 billion devoted to the
development of the CLV. Griffin apparently doesn't consider the man
rating business a serious impediment:

'Griffin has made it clear that he is not opposed to using EELV
vehicles effectively unmodified from their current versions to launch
crewed vehicles. In a May 2003 hearing by the House Science
Committee?s space subcommittee on NASA?s Orbital Space Plane (OSP)
program?a short-lived effort to develop a manned spacecraft that was
superseded by the CEV?Griffin noted that the term ?man rating? dated
back to efforts in the 1950s and 1960s to modify ICBMs to carry
capsules. ?This involved a number of factors such as pogo suppression,
structural stiffening, and other details not particularly germane to
today?s expendable vehicles. The concept of ?man rating? in this sense
is, I believe, no longer very relevant.?

'He argued that EELVs and other expendable vehicles are already called
upon to launch high-value unmanned payloads. ?What, precisely, are the
precautions that we would take to safeguard a human crew that we would
deliberately omit when launching, say, a billion-dollar Mars
Exploration Rover (MER) mission?? he asked. ?The answer is, of course,
?none?. While we appropriately value human life very highly, the
investment we make in most unmanned missions is quite sufficient to
capture our full attention.?

'The Atlas 5 and Delta 4 EELVs, he noted, have a specified design
reliability of 98 percent, in line with experience with the premier
expendable vehicles to date. If such a vehicle was used to launch a
crewed spacecraft equipped with an escape system of just 90 percent
reliability, he noted, the combined system would have a 1-in-500
chance of a fatal accident, ?substantially better than for the
Shuttle?.'

http://www.thespacereview.com/article/339/1

I gather than the stick would be a bit safer than the Atlas or Delta,
and I know that NASA wants a slightly more massive CEV than either can
handle, but I sure can think of some interesting things to do with
that $4.5 billion.

Also, some have been questioning the decision to launch the CEV
separately for moon missions. That's an extra $100 million or so per
moon mission . . .

I'm wondering too (and this relates to your other post) whether we
couldn't co-develop more of this with the Russians, Europeans, and
Japanese. With $4.5 billion for the CLV, $10-15 billion for the HLV,
$5 billion for the CEV . . . so we're talking on the order of $20-$25
billion. If we could save $4.5 billion by using EELV's, and shave
perhaps $10 billion by cooperating on the HLV and CEV, we'd have more
than $10 billion with which to do some very cool stuff . . .


--
Josh

"This is a devastating storm. This is a storm that's
going to require immediate action now." -George W. Bush,
four days after Hurricane Katrina
.

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