Ever heard the saying "It's not rocket science!"? It's often used by smart-asses who know nothing about rocket science. But then again, who does? It is, after all, super difficult. Well, NASA does, obviously, and back in the early 60s rocket science was even more complicated than it is now.
These days you can probably figure out how much fuel you need to get to the moon and back on a smartphone app, and if you want to know the weight of Neptune then you can simply search it on Google. But back in the 1961, scientists at NASA were still doing things with a piece of chalk and a giant blackboard. And believe it or not, they put the first US astronaut into space that very same year, a feat made all the more impressive when you remember that the electronic calculator hadn't even been invented yet (h/t: vintage everyday)
Image credits: J. R. Eyerman, via LIFE
Image credits: J. R. Eyerman, via LIFE