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Old June 7th 17, 12:23 PM posted to sci.space.policy
Rob[_8_]
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Default GSLV III Successful Launch

Jeff Findley wrote:
In article ,
says...
Same. India is in the same boat as every other launch company when it
comes to reuse. But, labor costs are far lower in India than in most
other countries launching payloads into orbit, so I'm betting they'll be
able to get away with being all expendable longer than say the US or
Europe (Russia is hard to tell).


It is always hard to tell. The cost per launcher of course goes down
when you make more of them, re-using launchers reduces the number being
produced and increases the cost per launcher. Re-usable launchers could
be more expensive to begin with. There are also costs for refurbishing
the recovered launchers (it is not like they are simply hoisted back on
the pad and re-filled) and there may be an increased risk of failure.
Making the launcher recoverable also reduces its performance.

Only the very naive will think "this launcher costs 50 million so when
we use it twice we go down to 25 million per launch and using it 10 times
our launch costs go down to 5 million".


SpaceX has already reflown one first stage and it reportedly cost them
less than half the cost of new (refurbishment cost versus the cost to
manufacture a new one). But yes, much of what they do is the same
regardless of whether the stage is new or used (like test firing it), so
you don't ever get to recoup those costs by flying a reused stage.


There can be a reduction in cost, but it is not obvious. Apparently
they now have saved some money (2 launches for 1.5 times the cost).

Still, they're saving money and they still have not "worked all the bugs
out of the process". This year, they'll start flying Block 5 first
stages which incorporate changes to make reuse easier and cheaper.
They're learning and improving.


When a refurbished launcher fails, and it turns out to be due to the
re-use, they need quite some launches to recover that cost.

Plus, you are ignoring the very real "infant mortality" problem. On an
expendable, there is always the possibility that some manufacturing
defect will creep into the vehicle causing it to fail. Since it's
expendable, its first and only flight is both test flight and
operational flight.


Of course. But there is also the problem of failures due to using a
refurbished launcher that may have damage or wear.

From the very beginning Falcon stages have been test fired before flight
(in Texas) to prove them out. So even on an "expendable" Falcon 9 first
stage, its first flight is not the first time it's been fired.


This is not specific for SpaceX, component and system tests are done
by other companies as well.

Also, note that even new copies of an existing passenger jet design are
test flown at least once before putting paying passengers on board.
Only the very naive would put paying passengers on the very first flight
of a newly built aircraft. Yet some people don't even blink when a very
expensive payload is put on top of a never before flown copy of a launch
vehicle.


I think there is still quite some difference between landing a passenger
aircraft, loading new passengers and fuel and taking off again for the
next flight, and re-using a Falcon launcher.
In the early days of Space Shuttle there was also the myth (probably
mainly among the public and press) that this space vehicle would operate
like a plane: land, re-fuel and take-off. In practice it was (or turned
out to be) quite different from that.