Zero-gravity tool, etc.
I wasn't aware, being very ignorant about space traveling, that operating on a human body up there could have such drastic and dramatic consequences.
That means that unless they solve that problem immediately, traveling would be utterly dangerous, because people get sick or have accidents all the time and coming back to Earth just to treat the injury sounds like terribly impractical, specially if they are already near Mars or whatever (the frustration for the crew!) and without mentioning --in these days of scarce economics-- the expense!
And will they have enough fuel for the trip back?
The injured person will die during the return just tired of waiting so long to be back home for the treatment.
