There's a great 25 minute tour of the ISS by Sunita Williams on NASA's YouTube channel along with commentary on how life works up there. <a href="https://youtu.be/doN4t5NKW-k" rel="nofollow">https://youtu.be/doN4t5NKW-k</a>
Swallowing your toothpaste. Yuck. Sometime I think human will never get anywhere near deep space if we don't solve our gravity-bound biology. The only way I see is when we digitize our brain. Eliminate biology altogether.