Here's some more sundry about RLVs and economics as
I see them.

Ian Woollard wrote:

> Yes. Or you find a very rich guy like Beal who 
> will fund most or all of the development.

Most rich guys don't get rich through being million
dollar philantropists.  They can be more long-sigthed
than VCs, and more patient, but they still expect to
make ROI.  Development costs need to be held within
reason or it will take too long to make returns for
it to be worth their efforts.

> Actually, I think that the first RLVs will have to 
> be profitable at a small fraction of current total 
> launch mass (or nearly so).
>
> If you make the RLV a minimum size, then launching 
> 100x, might only launch as much mass as one Shuttle.

While this may work in the long run, you'll still
have a long time before it makes sense.  Very few
companies make 300lb satellites.  Without some very
significant vertical integrations (basically also
building an orbital assembly facility), and having
all your customers redesign their payloads to be
launchable in that small of chunks, you won't get
too much payback anytime soon.  You may get a few
tourist flights (as you could fit another person
into something that size), but odds are that you
couldn't make return quick enough.  Making a RLV
that can fly 100 times in a year is not trivial,
and in fact a lot of the design *doesn't* scale 
down with size (though construction and handling
costs do scale a bit).

In the long run, it may make sense to break things
up this small, but it'll be a while before it does.

> No. It would take a few years to design a new vehicle
> anyway. Whilst you are doing that, you can be trying
> to sell contracts. If you don't manage to sell any;
> you might as well pack up and go home.

Here's the problem that you missed.  If you are 
talking about some ultra small RLV, you'll have a
hard time getting anyone to commit to you.  This
is due to the fact that if your system doesn't 
work, they're left completely stranded.  Now, you
may be able to pull off convincing them, but if 
you don't succeed, they take a huge hit.  People
don't like betting the farm on an unknown like that.

Now, Dave Salt idea (slightly bigger RLVs in the
7000lbs to orbit size) might make sense for the
current market, but then you also have to design
transfer vehicles etc.  This is a lot closer to
making business sense, as it doesn't require the
customer to make drastic changes in their billion
dollar systems to launch on your vehicles, and it
doesn't neccessarily require orbital infrastructure.
That is an RLV system that *might* actually make
sense at current flight rates (which was kinda
my point).

> Yes, but if your test flights generate an asset that
> you can borrow against, it helps. For example the 
> RLV company buys a bunch of rocket fuel at a few 
> dollars a kilogram. They stuff it in the nose of the 
> test vehicle. Launch it. If it makes it; great, you
> can potentially sell that payload; it's now worth 
> about $1000-4000/kg. If it doesn't- it didn't 
> actually cost you anything except the test flight, 
> which you were going to do anyway.

While this sort of strategy is wise, you're overlooking
some issues.  First off, that fuel must be stored in
some way that is useful.  You'll need to design the
system to keep it in orbit, to transfer it to others,
to store it, to allow docking or grappling, etc.  All
of these are quite doable, but take more than a few
bucks per kilogram.

Coupling this to your RLV development just adds 
unneeded risks, and having an asset that can't
be sold for a long time isn't always that wise.
Most companies these days are trying to reduce
inventory, and increase turn rates.


Rand wrote: 
> Only way to land without wasting too much fuel
> is to be really aggressive.  Operationally, this 
> requires a full up burn above abort altitude to 
> make sure the engines work, and that pre-landing
> burn wastes fuel and introduces new failure modes.

If the system is designed as a capsule with a
launch escape system (say if you wanted to make
it the upper stage of a TSTO), you can have the
hypergolically fueled LES act as a backup to
the normal rockets.  Would that help?

~Jon

_______________________________________________
ERPS-list mailing list
[EMAIL PROTECTED]
http://lists.erps.org/mailman/listinfo/erps-list

Reply via email to