Re: SpaceX Thought experiment -a Saturn V class vehicle within 10 years?



Ed Kyle wrote:
> Tom Cuddihy wrote:
> > The new update at SpaceX has got me cogitating.
> >
> > After Falcon V development is complete (LEO throw weight ~13,000 lbs,
> > GTO 4200 lbs), SpaceX will have a Merlin 2 engine with a sealevel
> > thrust ~100,000 lbs, enabling SpaceX to compete against the lightest
> > versions of Delta IV and Atlas V. Falcon V in that configuration would
> > have a GLOW ~500,000 lbs.
> >
> > The next obvious step would be a Falcon X, which would compete with the
> > heavier versions of EELV (~30,000 lbs to GTO), presumably with a GLOW
> > ~1.5 million lbs. With 5 engines like Falcon V, 'Falcon X's' Merlin 3
> > or whatever would need ~300,000 lbs sealevel thrust. Then you have a
> > third generation vehicle with a third generation engine--> and nowhere
> > to go with it.
> >
> > If, on the other hand, you take SpaceX at their word that they intend
> > to develop a ~1.5 million lb thrust engine in the next few years,
> > perhaps there will be no 'Falcon X'
> >
> > Instead, a bigger version of Falcon I, call it 'Gigantor I', with one
> > Merlin 3 at 1.5 mil lbs thrust, as the lower stage. You probably save
> > some weight in the stage with one engine, with similar reliability to
> > Falcon I but the ability to carry heavy payloads--and no solids. Assume
> > the 1.5 mil thrust engine costs 3 times as much as the Merlin 2-->
> > still you're at <25 mil for the Gigantor I engine.
> >
> > Now put 5 Merlin 3 engines on the lower stage--you're talking about a
> > vehicle with GLOW of 7.5 million lbs. Now you're dealing with a Saturn
> > V class vehicle (Gigantor V), with the ability to put >150 tons in
> > orbit. Perhaps for a recurring cost of less than $200 mil.
> >
> > thoughts?
>
> Before you have SpaceX building a Saturn V, consider
> that this company has not yet even tried to launch
> its first small rocket, let alone succeeded.
>
> The Falcon V of which you speak is currently nothing
> but drawings and piles of parts and stock aluminum,
> with some parts welded together. There is talk of
> putting the first five Merlin engines together for
> initial testing late this year or early next, but
> consider that it took von Braun and company nearly
> a year to get their first cluster booster fully up
> and running on a test stand.
>
Von Braun and company were using an engine bigger than any ever made
before, were trying a concept never tried before, and were putting it
all together using multiple government contractors using sliderules,
not finite element modeling.

It may indeed take along time before the Falcon V first stage is up and
running on a test stand. But unlike ze Germans, it won't be because
they're trying something no one has ever done before.

> The Falcon V version that purportedly will be built
> from those bits and pieces is far short of a match
> for the smallest EELVs. If it can be made to work,

to be precise, it has a lower payload capacity than the lightest
version of BOTH EELVs. And a price 1/6th as high to launch.

Using the Merlin 1B engine. If SpaceX does indeed proceed with a Merlin
2 development of ~100,000 lb sea level thrust & similar performance to
Merlin 1, it will probably match the lightest EELVs.

> it will only be a Delta II class launcher - and then
> only on paper since SpaceX will still be decades
> behind the Douglas-McDonnell-Boeing Thor/Delta
> learning curve. (At 574 launches, Thor/Delta is the
> world's second-most flown rocket after Russia's R-7.)

Don't look now, but Delta IV is not exactly similar in any way to Thor,
other than being launched by the conglomerate that bought the company
that bought the company that originally launched Thor.

Before you go pshawing Spacex's institutional experience with regard to
launchers (especially compared to Boeing), you might want to check out
the "people" on SpaceX's website. They ARE pretty much the best and
brightest from McDonnel-Douglas space.
>
> The projected liquid hydrogen upper stage that could
> make Falcon V as powerful as a Delta IV Medium is not
> a trivial thing to develop. Years and many tens of
> millions of dollars yet before we see that stage,
> if ever.

they may try to develop a hydrogen upperstage far in the future, after
they are a public company. But I doubt it. It's neither simple nor cost
efficient. I think it far likelier that they will stick with Lox/RP-1
and just grow the rocket. Unlike government supported space companies,
SpaceX is going to have to leverage existing technology rather than
trying to continually develop the next breakthrough.

>
> But even when and if SpaceX gets Falcon V flying,
> Musk will have spent maybe $100 million on the
> effort. It would take hundreds of millions, maybe
> even billions, of dollars more to develop a
> Saturn V class rocket. (Kistler is looking for
> $500 million that it needs to complete its K-1).
>
> Musk doesn't have that kind of money. He is only a
> multi-hundred millionaire. (Yes, he sold PayPal for


Yes, but if Falcon V gets off the pad in a reasonable time frame (the
next 3 years), Musk will, if he's sane, take the company public or go
for a round of additional private financing before going for a new
rocket.

> more than a billion, but he had to use much of the
> proceeds to pay down debt he used to leverage the
> company's development). He certainly isn't going to
> make that kind of money selling Falcon V launches
> at $12 million a pop.

.

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