Personality factors in Astronaut selection are becoming especially important on the eve of space missions of extended duration. But psychiatric selection is fraught with imperfections and inadequacies. To compensate for these, the author presents a "back-up" system which involves the psychiatrist in a step-ladder type of monitoring of space crews during their training. Direct contact between psychiatrist and crew member is minimized; the system makes primary use of flight surgeons.Abstract Teaser