>>Researchers say that when humans return from a planned visit to Mars in the 2030s,
One way trip.
And even the Apollo astronauts were quarantined.
Also see
The Andromeda Strain (1971) Trailer
https://www.youtube.com/watch?v=YMbSpnlOOtE
One way trip .
True. Watch the 1977 documentary titled Capricorn One. ;)