By "destroy" I mean invasive inspection methods. For example, I'm assuming a retro-burn will experience more base heating than just an ascent burn. And farther up the stage, impinging on mostly empty tanks. Perhaps you'd want to drill samples from the metal to see how it stood up to environment. Or look at cross-sections of plumbing or wiring in and around the engines and thrust structure.
These are guesses on my part, of course. Maybe it's not needed.
Good points.
Actually, keeping F9-21 for a museum rather than refly it, does not necessarily mean that closer inspections of it would not be allowed to damage it to some extent.
Such as, cutting out some small samples for metallurgical testing, along the lines of what you said.
Cutting some holes for access to wiring or other inaccessible components. Even cutting off parts and re-welding them back on later. Even to allow a person to fit "inside" certain areas, if need be.
Stuff that would totally ruin the booster for re-flight purposes. But as long as it could be reassembled and either patched over or even make a "feature" out of noting areas that were cut for thorough inspections, I could totally see that. Not as ideal as superficially leaving it as it is, but understandable.
Indeed, for the sake of R&D, it makes way more sense to inspect it to the point that it may be damaged too much to refly it.
So in a way, the "keep it" statement, the primary reason may be more due to it being unable to fly after some invasive and potentially damaging inspection methods. While "oh by the way", when they are done thoroughly inspecting it, it can go to a museum. And even at that.....there's no guarantees that if it does make it into a museum, that the 9 engines that flew on it will all be there (this assumes nothing goes badly during the static tests, and yes I know the too true famous Benny Hill joke).
There was some Apollo CM I saw in a museum, possibly even Apollo-11's Columbia, that had core samples cut out of the heat shield.
And last I saw Enterprise long ago (2008, when it was at Udvar-Hazy), it still had plastic wrap covering the LE area where some RCC panels had been removed for testing for the Columbia accident, to see whether a high-speed Foam strike could indeed damage them.
Now if Musk decrees that F9-21's core not be visibly damaged at all by further inspections, then that's that. But otherwise, I think at least some degree of damage for the purpose of inspections would be on the table. That's not the most sentimental thing, but Rocket Science (R&D) and a Space Launch Company's future should be more important in this case.
- George Gassaway