From: Technotranscendence (neptune@mars.superlink.net)
Date: Sun Jul 14 2002 - 10:22:04 MDT
On Sunday, July 14, 2002 11:27 AM Robert J. Bradbury
bradbury@aeiveos.com wrote:
> It turns out Spike is pretty much correct.
How could this be?:)
> The great god Google turns up this link:
> http://www.hq.nasa.gov/office/pao/History/SP-4009/v2app2.htm
> which is part of "The Apollo Spacecraft -- A Chronology".
> NASA SP-4009.
>
> The total mass of the spacecraft is ~40,000 kg, nearly 42%
> of which is fuel.
>
> The lift capacity of the Saturn V into NEO was ~118,000 kg.
> I'm guessing the difference is in the requirements getting
> into a lunar injection orbit. Either that or the Saturn V
> was way overengineered for its job since at the time they
> started designing it I think they hadn't developed the
> lander concept which saves you a lot of fuel not having
> to take the command module down to the lunar surface and
> lift it off again.
Probably was overengineered for safety reasons too.
> Given a Shuttle/Delta V lift capacity of 20-23,000 kg, you
> could do it in 2 missions. If you could harvest the fuel
> in space you could probably do it in 1 mission.
>
> If done with Shuttle missions, 2-3 would run you $800M-$1200M at
> the going price of $400M/mission. I don't know if Boeing
> has released prices for fully configured Delta IVs yet.
> You ought to be able to come close to doing it with a single
> Energia mission, whose price in 1993$ was ~$110M.
>
> So I'd tend to agree that we could go to the moon if we
> wanted to, especially if one used the ISS as an assembly
> station.
ISS assembly or something similar does offer one advantage. Stuff can
be packaged and assembled in orbit. It needn't be designed from the
start to fit together as one piece and make it through the atmosphere.
This removes some limits on design.
It also offers an advantage I mentioned earlier of testing stuff before
sending it off. Thus, a LEM could be tested in Earth orbit -- insuring
it works after it's trip or assembly there -- rather than tested in use.
I'd hate to find out my LEM stopped working because of detectable
probably I only discovered once I'd landed -- or while I was landing.:@
> But you have to get the costs down. That means either space
> based harvesting of fuel, preferably from NEOs, as has been
> suggested or you have to get the Earth-based launch costs
> way down.
Or using some exotic methods. For example, taking the unmanned return
module to Luna separate via solar sail or ion thrust. It can then be
landed and all the actual humans need to is land on the Moon and return
via a separate vehicle. That's risky, but doable, IMHO.
> I tend to disagree with spike in that I don't think small
> people will buy you that much. And we certainly aren't
> going to have the ability to engineer them anytime soon.
> My bets would be on real AIs before munchkins.
I agree. I'd also rather start space and solar system settlement
yesterday -- not wait for genetic engineering to get it started. That
would only add to delays. By that standard, why not wait until we have
humans that are built like rockets?
Cheers!
Dan
http://uweb.superlink.net/neptune/MyWorksBySubject.html
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