On Sun, 12 Feb 2006 16:55:09 -0500, in a place far, far away, "Will
McLean" made the phosphor on my monitor glow in
such a way as to indicate that:

No, I told you. Add up the development costs,

The CEV is also intended as a moonship and marsship and lifeboat. You
can't allocate all the development costs to the LEO ferry role.

I'm not. I'm including the cost for lunar flights as well (and I
think that the notion that it will be used for Mars is hype, not
reality).

and the ongoing
operational costs (including the costs of launching the cargo that is
no longer launched by the manned vehicle, but can be by the Shuttle),
divide by the flight rates, and you get an infrastructure that costs
as much, or more than, the Shuttle. Even ignoring the amortization of
the development costs, the marginal costs of the Shaft + CEV launch
will be at least a couple hundred million, to deliver four crew
instead of seven. Shuttle's marginal cost are about the same, to
deliver a crew of seven, plus fifty thousand pounds of payload.


The CEV is sized to carry up to six, and the shuttle can't carry
anything like fifty thousand pounds of payload to ISS.

I wasn't thinking ISS per se, just LEO. But it can still carry a lot.
And bring it back, which CEV will be unable to do.

NASA figures
that it can do the ISS crew rotation and logistics with six or seven
CEV flights.

I assume that that's why they've oversized the CLV--otherwise, you
could have a lot smaller vehicle that could just deliver the crew in a
CM, and then mate it to the SM/LSAM in LEO. OK, so what's their
estimate of the costs for those six or seven flights?

Marginal costs for the shuttle include failure costs

No, they don't. Average costs do, but not marginal costs.

since the shuttle
has historically suffered an orbiter loss and multiyear standdown every
fifty flights or so.

What makes you think that CEV/CLV won't have failures and standdowns?

Also, shuttle maintains the standing army to
service a large, complex, finicky tile covered orbiter with wings,
control surfaces, hydraulics, landing gear and maintenance intensive
main engines.

The army may not be as large, but if you think that CEV won't have
one, you're fooling yourself.