My RLV data (X-15, X-33, X-34, & the Space Shuttle Orbiter) shows all but
X-34 costing more, per pound, than the lowest cost ELV (before Falcon
9); X-34 was very slightly more, close enough to call even.
The Falcon 9R stage is clearly more costly than the expendable version as
it carries additional hardware which must cost more.
Bill
On Saturday, January 9, 2016, Edward Wright <edward.v.wright@xxxxxxxxx>
wrote:
The details matter: RLV's cost more per unit than similar ELV's,
That is a common assumption, but where is there data to support it?
General Dynamics did a study in the 1960's comparing reusable and
expendable vehicles of similar performance (Atlas A and the X-15). They
came to the conclusion that the reusable vehicle cost about 60% as much to
develop. The Air Force did a parallel study at the same time, using
different methods, and came to the same conclusion.
One can argue that orbital RLVs are different, but that's an argument, not
data. You can look at the estimates of RLV development costs, but those are
only estimates based, more likely than not, on the *assumption* that RLVs
are more expensive. It's impossible to do a like-to-like comparison of real
data because no one has built an fully reusable orbital vehicle.
Max Hunter used to say that people who believe RLVs are more expensive
forget that to build a rocket, you need to fly a rocket. A rocket that is
cheaper to fly operationally will also be cheaper to flight test. Anyone
who believes RLVs are more expensive must show other expenses to offset
those savings.
ELV testing costs also tend to be understated because ELV developers skimp
on flight tests and push a large portion of the cost/risk to early
customers. An ELV might fly "operationally" for years, even decades, to
reach the demonstrated reliability that an RLV might achieve during the
development flight-test program.
