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Old September 14th 18, 07:44 PM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Falcon 9 Block 5 update

JF Mezei wrote on Fri, 14 Sep 2018
13:51:58 -0400:

On 2018-09-14 06:17, Jeff Findley wrote:

Right, and Vulcan will still have a first stage separation event, so
they're adding significant complexity to the vehicle to only get the
engines back. Why not add a similar, proven, amount of complexity to
get the entire stage back in one piece?


Aren't they expecting to catch thsi by helicopter ?
This saves on the cost of software, sensors of making the stage land
itself (as well as landing gear).


But it requires putting a helicopter in the path of the falling
engine, which is a great way to knock down a helicopter and requires a
sufficiently precise reentry to be near the helicopter.



The only bit of IP ULA might not have to do a VTVL is the software.


And the money to lose a number of stage 1s during initial
development/testing (as happened with SpaceX).


As opposed to how many engines and helicopters they'll lose?


On the other hand, what are the rates of succesful recovery of engines
that fall down from the sky?


Zero. Particularly with helicopters.


One plus sign: this scheme results in steady production of stages,
whether they succeed in recovering engines or not. Only the production
of engines is uncertain since they don't know how many they will
recover. Small consolation prize I know, but was trying hard to find
some positive.


The engines are a huge part of the cost of the total stage.


--
"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."
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