Six to twelve month earlier with the exception of a few rate EVA sorties.

Six to twelve month earlier with the exception of a few rate EVA sorties. Organized in a hurry, the vast majority of them are prepared with in advance. you have to make arrangements with the schedule of incoming flights and the number of astronauts: the agencies don't really like to send their astronauts out it there are only three people in the station, because there are always two people security reasons...and that a single person on the ISS is not enough to manage of EVA outing. Because its a team sport! Two astronauts in the spacesuit, but also a person manage the airlock, sometime also in the rebotic arm to be piloted from inside the station. on the ground too, you need personnal: a CAPCOM, a person who will be able to react quickly in the event of a question or concern.