FYI, here's a NASA page about ISS transition: https://www.nasa.gov/faqs-the-international-space-station-tr...

Quick summary (avoiding duplicating points other posters have already made):

* NASA's current plan for post ISS operations is to not be in the LEO space station business. NASA wants to buy LEO manned services if required from commercial operators (the same way NASA has left the business of delivering cargo and humans to the ISS). NASA will focus manned operations effort on beyond LEO.

* NASA has submitted an RFI asking for commercial interesting in re-suing major components of the ISS and says that it received no viable submissions.

Anything launched is assembled from parts that have been certified as fit for purpose, voluminous paperwork showing the examinations, testing, etc, all to try to minimise the risk of failure. Once it has been in orbit for years or decades, facing ten thermal cycles per day, bathed in elevated radiation and ions, and pitted with micrometeorites, you'd really want a thorough examination before reuse (X-ray ultrasound, etc: not yet available off-world)

It would be far harder and more expensive to reuse parts.

Just because there are mechanical parts and doesn't mean that they are reusable or serviceable.

Humans have basically no ability to do any manufacturing construction or service in space. It takes an 8 Hour Eva to change a couple bolts, risking human life all the time.

Bringing all of the tools and equipment to space to facilitate reuse would require far more than simply replacing it.

On top of that, most of the space station is worn out and far beyond it's design lifetime.

And consider that the Space Shuttle was used extensively late in its life to help build the ISS. We have nothing similar to help build another one. I'm sure there's good reasons to do it (hopefully not just budgetary ones), but it's unfortunate that we're deorbiting it at all. The cost of maintaining/upgrading the one we already have probably pales in comparison to the cost of ever building another one.

If there was more industry in space, it would make some sense. The problem now is there isn't enough demand for it, and if you don't maintain the orbit for this stuff, it'll cause problems. The most likely problem is that it'll do a uncontrolled re-entry somewhere on Earth and hit someone. The other possibility is it'll wander in its orbit and smash into something else in orbit.

Also, if it's not big enough to monitor it can disappear. Radar makes it hard to track anything that's not huge and actively transmitting.

The US will never build another station at the inclination of the ISS. That was solely a concession to satisfy Russia so they could be a partner. Moving that equipment to another orbit isn't economically feasible.

Some have the same idea:

https://spacenews.com/industry-sees-missed-opportunity-in-de...

> Industry sees missed opportunity in deorbiting ISS

> “As technology matures, certainly in the next decade we’re going to get to the point where we’re going to be able to reuse and recycle a lot of these materials,” said Ron Lopez, president and managing director of Astroscale U.S., a company working on satellite servicing and debris removal technologies. “Instead of letting it burn up and lose all of that economic value, you take it to a foundry in space” and break it down into raw materials, he said during a Satellite 2023 panel March 16.

Easier said than done though.

There is also the question if the ISS, despite construction costs of hundred billion dollars, is really much worth in a decade. When Starship is flying you could use a modified rocket itself as a space station:

https://arstechnica.com/space/2023/07/could-spacex-turn-star...

If we have on-orbit refueling and Starship on or before 2031, it would be possible to "park" the ISS at the Earth/Lunar L4 or L5 Lagrange points. Conversely it could be parked in a solar orbit far enough out to not interfere with geosynchronous satellites but close enough that a small tug to move it up or down to maintain spacing with the Earth.

Given its mass, either option would require significant delta-v to get it parked. The L4 and L5 points have the advantage that it could pretty much live there without worrying about station keeping.

I expect its possible to do it with a series of Falcon 9 launches of several tug craft but the co-ordination of that would be very difficult to pull off.

We don't even re-use parts on cars, which should be many times easier to re-use than parts on the space station

also: https://inaccessibility.net