You climb in, seal the hatch, turn on a little oxygen, turn on the scrubber, which removes the CO2 in the air you breathe, and they chuck you overboard. Down you go. There's no connection to the surface apart from a pretty funky radio.
Uno se sube, cierra la escotilla, prende el oxígeno, prende el filtro de gases, que elimina el CO2 del aire que uno respira, y te tiran por la borda.