Every guest spends fourteen days on the Atacama plateau before flying. The altitude is part of the reason — San Pedro sits at 2,400 metres, and the body that has adjusted to thin air copes better with the first hours in orbit. The sky is the other part: it is the darkest and driest on Earth, and the nights are for looking up at where you are going.
The centrifuge is the part people fear and the part they talk about least afterwards. The parabolic flight is the part they talk about most.