During the early days of the space race the public relations handlers at NASA had an image to uphold. America's astronauts were the new face of a nation: they were the bold, brave explorers of the beyond. But this image didn't always align with the more rough-and-tumble types who got the job.

Barring a couple of scientists, almost all of Americas early astronauts had moved over from the military. Many having been experimental aircraft test pilots—a job not exactly known for its dependence on decorum. As space history writer Amy Shira Teitel notes, some astronauts had trouble maintaining family-friendly language, and NASA went to sometimes great lengths to keep that fact under wraps.

In some cases, as Teitel covers in her Vintage Space video series, sometimes this censorship amounted to little more than scrubbing down transcripts—replacing “farts” with “gas” and cutting a few f-bombs. (Caution: the video contains cussing.)

In other cases, however, NASA took great pains to clean up astronauts' language. A few years ago Teitel wrote about the space agency's trick to harness one unnamed astronaut's filthy mouth:

One [astronaut] in particular had the unfortunate habit of filling space when his mind wandered with profanities. This posed a problem for NASA - with the world watching astronauts walking around the lunar surface, how could the organization be sure the his transmissions from the Moon would be family-friendly? In preparing for his mission, NASA had the astronaut hypnotized. Rather than curse, a psychiatrist put the idea in his head that he would rather hum when his mind wandered. The hypnotized astronaut is rarely named, but only one man can be heard humming as he skipps across the lunar surface. Transmissions from Commander Pete Conrad are punctuated with "dum de dum dum dum" and "dum do do do, do do" making him the likliest candidate.

Even today astronauts maintain a largely squeaky clean image (best personified, perhaps, by former Canadian astronaut Chris Hadfield's endearingly non-threatening mustache). But just as before, what we see on the surface isn't all there is—the inner lives of astronauts in orbit are filled with frustrations and annoyances, and, probably, a few interlaced swears.