Astronauts (have to / don't have to) take the space shuttle to get to space.
have to
Astronauts (have to / don't have to) wear space suit outside the space station.
have to
Astronauts (have to / don't have to) be scientists.
don't have to
Astronauts (have to / don't have to) leave the space station.
have to
Astronauts (have to / don't have to) come home to Earth.
have to
