JF Mezei wrote on Thu, 27 Jun 2019
11:47:09 -0400:

On 2019-06-27 06:55, Jeff Findley wrote:

flight worthy Merlin vacuum engine. And from what I've read, SpaceX
does not believe that the booster will survive the test. Some reports
have said they don't even plan on trying to recover the booster.

Recovery would be interesting from a forensic point of view. at Max Q
altitude, are videos of the craft precise enough that recovering the
wreckage would not yield much info?


What info do you need?


Would it be correct to state that there are 2 scenarios where in-flight
capsule eject would be triggered:

-catastropic failure of lower stages. (eg: explosion)
-failure of guidance and stack headed for downtown Manhattan and capsule
gets to eject just before self destruct for stack is activated ?

In the second case, is there a choreography challenge to ensure the
ejected capsule doesn't end up colliding with the rocket that is still
under power until detonation?


No. The capsule accelerates away from the stack. That's sort of the
point.

So they're planning on expending an entire Falcon 9, minus one Merlin
vacuum engine, for this test. That's got to be hardware worth tens of
millions of dollars.

SpaceX undoubtedly has a "max re-use of X times" for Falcon 9s at this
point. (X may increase later on). If they have a rocket which has has
its X reached, it has no commercial value left and could be used for
such a test. And with such a test, help validate Faklcon9 for X+1 re-uses.


They have no such rockets. Nothing is anywhere near flight limits. I
suspect SpaceX chose this route because it's really the only way to
actually test it. Simulations are nice and all, but the data you get
from them is no better than the accuracy of the simulation.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn