What Comes After the ISS?

 We just celebrated 20 years of continuous occupation of space...

...most of it in a station that was designed to last 15. The stubborn leak on the ISS is a symptom; the station is seriously showing its age. The ISS is still safe and might even last another 10 to 15 years, but building its replacement is becoming more urgent.

There's two roads being taken. The first is to Theseus' boat the ISS. The ISS has always been a modular station, and the idea is to add new modules and then remove old ones, or separate the new modules so they can orbit on their own. Axiom Space already has a contract for the first of these, which will apparently include a glass "Earth Observatory" from which astronauts will be able to watch their home world. Bigelow has already added an inflatable module which is used only for storage, and has now designed one that's not much smaller than my apartment...a lot of square footage for space, especially as in space you can use all the surface area.

Meanwhile, Blue Origin has decided to abandon the ISS altogether and simply start building their own station, eventually working towards full space habitats with spin gravity and the works.

Either way, the ultimate fate of the ISS is going to be a controlled deorbit with the station being intentionally burned up in the atmosphere.

Except for any bits that we choose to keep up there and eventually put in a museum.