"'We have discussed enclosing it, but those plans are not finalized yet,' said Protze. 'We brought the best of the best in to redo the rocket, inside and out, and so I feel confident that if it was to stay outside, it would be good for another 20 to 25 years.'"
You don't understand. Museums are a business, a nonprofit and often subsidized business, but still a business. The public is less served and engaged and exited per visit/hour/etc seeing pristine vehicles from behind a rope in an air conditioned building. Letting the public visit these things in the most ideal setting (which is typically whatever is closest to operating conditions) and ideally interact with, walk through and touch them is what builds appetite for further museum funding, expansion, etc.
After decades of environmental wear from outdoor display it can be moved inside, assuming there's enough public interest to justify that. The degradation of visitor experience at that point is acceptable because the item is older, more "historical" etc. The restoration of the item and subsequent redisplay itself then generates further public interest and/or revenue (especially in the modern age of Youtube and the like).
People need to interact with the stuff that their parents or their parents parents remember in order to get exited about (and fund) preserving the (best of) stuff that nobody alive has any connection to. You need to let patrons today sit in the Huey grandpa served in order to get the money to restore the Ford Trimotor nobody alive has much connection to. This is the same situation but bigger. The fact that the shuttles were a national prestige project and their location is a subject of national politics may cause emotion to mask things but on a 10+yr timeline the reality is the same.
This is something that maritime museums have long since figured out.
Sure sounds like you're trying to "justify a preconceived opinion".
> The public is less served and engaged and exited per visit/hour/etc seeing pristine vehicles from behind a rope in an air conditioned building.
The Smithsonian's responsibility is, in part, to many, many future generations of the public.
> Letting the public visit these things in the most ideal setting (which is typically whatever is closest to operating conditions)…
Again, that's either a hangar, or space. "Outside" is the spot it spent the least time, and visitors don't hugely appreciate a vacuum chamber from the inside.
> The degradation of visitor experience at that point is acceptable because the item is older, more "historical" etc.
That's essentially the opposite of how these things work.
> This is something that maritime museums have long since figured out.
The rockets are mostly painted metal while the shuttle's white surface is mostly a woven thermal protection blanket material. Significantly different materials more likely to be damaged in the elements.
After irreparable damage?
> There will be new artifacts.
There are unlikely to be new Shuttles.