In article ,
says...
And who do you think is going to pay for that? The entire life of the
RS-25 engine program was about reducing maintenance requirements and
they apparently have decided that that is a mug's game and are now
going in the other direction to lower the cost of the engines. You
just want to go that one step further and invoke magic and
unobtainium. High performance engines like RS-25 will ALWAYS be 'less
reusable' than lower performance engines like Merlin or Raptor. Just
look at chamber pressures. RS-25 runs twice the chamber pressures of
something like Merlin, with all that implies for pumps, wear, etc.


Excellent point. To put this in terms JF might understand:

The SSME is like the engine in an Indy car or F-1 car. They are
extremely high revving engines designed for maximum acceleration and
high sustained speeds. They might be good for more than one race, but
why take a chance of your engine blowing up? So, they're torn down far
more often than what your average car owner would consider "reasonable".

For an average American production car like a Dodge Challenger Hellcat
(which has a 700+ horsepower Hemi which isn't very high revving) would
be considered "fast". The Dodge Challenger Hellcat is also fairly
reasonably priced considering its performance. And do note that the
average Hellcat owner is never, ever going to push their engine anywhere
near as hard as an Indy or F-1 engine is pushed, even if they take it to
the local drag strip on the weekends and do a few 1/4 mile runs every
month.

Jeff
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