We didn't learn any of that from the ISS which we didn't already know from Salyut 6 and 7, and Mir. The ISS, aka Mir 2, hasn't taught us anything new. The rea

We didn't learn any of that from the ISS which we didn't already know from Salyut 6 and 7, and Mir. The ISS, aka Mir 2, hasn't taught us anything new. The reason it exists is because decades ago, for a few years, manned space stations made sense for orbital reconnaissance because putting unmanned cameras in space was complicated. Salyut and MOL were born from this transient strategic necessity. Unmanned recon satellites soon became practical though, so MOL was canceled but the Soviets carried on with Salyut because if there was anything they were good at, it was continuing to make something long after anybody else would have canceled it. Even when they did get recon satellites they did it with Vostok capsules, they never stopped making those after launching Yuri Gragarin in one. They just kept on making them because they were already tooled up for it, finding new excuses to keep making the same old stuff. And so it was with Salyut, the program was obsolete for orbital reconnaissance but they were already making them so they kept at it, turning it into a national prestige program. Mir was a direct descendant of it, built around the DOS-7 module which was a Salyut module with 6 docking ports instead of the two on DOS-6. It never had a good reason for existing besides Soviet politics. (By the way, Skylab never had a good reason for existing either, just politics. NASA trying to hold onto their funding as Apollo was wound down.) The ISS is nothing more than Mir 2, built around the DOS-8 module, it's a Salyut with American funding because this time America wanted to keep the Russian space program solvent to make it harder for Iran/etc to recruit that Soviet talent. And because NASA likes long term projects that require around the clock staffing because that's great for budgets and careers. That's why the ISS exists. Also we aren't going to Mars. Sorry. A lot of individuals are passionate about that but at an organization level there is no drive for it. NASA likes to use the talk of it for fundraising but never makes progress on it and Congress won't ever greenlight it, and SpaceX uses it to keep their employee moral up but all they are demonstrably working towards is being the king of launching satellites. The only money to be made in space is with stuff pointed at Earth. There is no economic case for Mars colonization. It's not happening. I wish it weren't so because I'm a sci-fi junky, but it is what it is.