Re: Lunar Lander in a 5.2m faring?


Rüdiger Klaehn wrote:
> Fred J. McCall wrote:
>
> [snip]
> > :The Russians have been transferring storable hypergolic fuel and oxidizer
> > :from Progress tankers to their stations (including ISS) for years. No EVA
> > :or clumsy pressure fittings seem to be required for this to work.
> >
> > Now you might want to look at the thrust developed and burn durations.
> > I don't see any of those vehicles going to the Moon, landing, and then
> > taking back off.
> >
> So let me get this straight:
>
> scaling up from the several hundred kgs the russian progress routinely
> transfers to the ISS <http://www.russianspaceweb.com/progress.html> to
> the tens of tons required for a lunar mission is so complex that it
> can't be possibly be finished until 2018.
No. The only reason for the current envisioned delay to 2018 is to
allow a funding delay in developing a SDHLV due to the perceived need
to continue funding shuttle until 2010.

>
> But building a huge heavy lift vehicle out of shuttle components has
> negible technological risk?

negligable on-orbit technical risk, especially compared to on-orbit
assembly and fuel transfer operations. If shuttle and ISS have proved
one thing, it's that on-orbit technical risk should be traded for
ground technical risk wherever possible.

>
> Orbital propellant transfer of storable propellants and even mild
> cryogens such as liquid oxygen and liquid methane is not that hard.

says you.

> There are even materials which remain flexible at liquid oxygen
> temperatures, so you could use a simple bladder system. It is just that
> nobody has ever seriously tried to do it.

Probably because it's just so simple. simple is boring... ;-)

Tom

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