Heh heh.
Not sure what they have up there now, but at one point apparently they had 68 A31's and 32 T61p's. It's hard to tell whether something is a T500 vs a T61p, I think?
When you check out a video of the inside of the station, you can quickly see why they like Thinkpads: the Trackpoint is essential - there are no mice anywhere!! For example, check out "100 ThinkPads in the ISS above us" posted was back in 2014:
https://www.youtube.com/watch?v=E4Xyl4cW5yc
It gives you a view of all kinds of Thinkpads all over the ISS. And you can see that practically all the laptops are held up by various laptop arms, so they need to have some kind of built-in mouse control. I guess these days you could have a trackpad, but up until the last 10 years or so, if you were running Linux or Windows, then the trackpads kinda sucked compared to the Trackpoint. Macs were the only machines with good trackpads back then, and no one is going to take a Mac up in space. Macs barely knew what an enterprise network was 10 years ago, and if you wanted to plug something into a Mac that wasn't made by Apple then you'd be SOL. Whereas, you can bet that they are still bringing up new devices to the ISS and plugging them into these old machines and making them work today.