"Andrew Gray" wrote in message
. ..
In article , Tom Merkle
wrote:
I wonder how Elon Musk slipped this one under the radar. According to
this article:
http://www.thespacereview.com/article/70/1

Elon Musk says the follow on to Falcon I will be a vehicle called
Falcon 5, which will essentially use 5 clustered Merlin engines
(Falcon I uses 1) in a Saturn-V like configuration, with an additional
Merlin on the upper stage. Musk claims this configuration will cost
approximately $12 mil to launch. That compared to the Falcon 1 at $6
mil. By my reckoning, that means Musk anticipates launching Falcon 5,
which has 6 Merlins on it, and presumably some other complex design
differences too, for only twice the price of Falcon I.

Does anybody see any way this makes any kind of sense?

Simplest explanation - launch costs (x per launch) and flight costs (y
per engine)

FI - $6m - $x+$y
FV - $12m - $x+$6y

12 - 6 = x - x + 6y - y
6 = 5y

so an engine costs $1.2m & therefore launch costs are $4.8m

(where "engine" = "hardware associated with an engine, inc. a share of
the rest of the rocket, assumed proportional" and "launch costs" =
upfront costs per launch, relatively constant regardless of what it is)

This is blatantly not the case, but it explains how it might work.
Nothing insane, just maths :-)

Couple of quotes from spaceX.com monthly updates:
---------------------------------------
We received preliminary approval for our flight termination system design
and have placed parts orders with key vendors. This is one of the most
expensive sub-systems on the vehicle, since we have to use a lot of
pre-qualified hardware (qualifying new hardware can take up to three years).
This and the avionics system stay almost constant independent of launch
vehicle size, so it is really impossible to optimize a small launch vehicle
on cost per unit mass to orbit
-----------------------------------------
Most of our propulsion efforts in May were focused on the Merlin turbo-pump
testing at our facility near McGregor, Texas. This is the most expensive and
mechanically challenging component on the rocket and typically where launch
vehicle developments have experienced the most difficulty.
-----------------------------------------
Environmental work continues at our Vandenberg launchpad (3-West for those
that know the base) and will hopefully be done in the next few months with
the help of the 30th Space Wing. The paperwork associated with this process
is surprisingly large and time consuming, particularly given that Falcon is
much smaller than vehicles that have been based off this pad before and is
completely non-toxic.


It'd be very interesting to see approximate cost breakdown by different
components of this particular launch vehicle, including operations costs of
one launch.

-kert