Jeff Findley wrote:

In article . com,
says...

On 2017-05-15 14:09, Fred J. McCall wrote:

percentage of the cost basis of the engine. For rockets the cost of
fuel is almost irrelevant to the cost of operation, so trying to
compare to aircraft is comparing apples and aardvarks.


The numbers given by Elon Murk show cost of fuel is minimal compared to
cost of new rocket.

However, in an environment where re-use becomes common, cost of turn
around (incl engine check/maintennce) and cost of fuel become the big
ticket items, just as is the case for commercial aircraft.


We're a long, long way from fuel costs being an issue. The first Falcon
9 first stage to refly cost SpaceX refurbishment costs less than half
the cost of building a new stage. As far as I know they didn't say
exactly how much, but we can guess if it was really 1/4 the cost they
would have said 1/4 instead of 1/2. At any rate, fuel is less than 1%
of launch costs, so refurbishment costs are still the lion's share of
reflight costs.


External estimates in the past have put the cost of reusing the stage
at around 10% of the cost of the original stage. That feels high to
me. If you judge by what Musk has put forward for ITS operation,
reusing the booster costs about 0.1% of the original cost. This
ranges up to 5% for the actual spacecraft (2nd stage). He also
expects to get 1,000 launches out of the booster. The spacecraft gets
around a dozen relaunches, so that 5% figure may be about right for
Falcon stages.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw