 What is the “space cafard” that Si describes?
What's more important—Man's conquest of space, or one spaceman's life? They also had a banquet for him, complete with speeches by such bigwigs of the Department of Space Exploration as Academician Lofting Gubelin and Doctor Hans Girard-Perregaux. There on the long, long haul to the Jupiter satellites, fearfully checking the symptoms of space cafard, the madness compounded of claustrophobia, monotony, boredom and free fall. Possibly somebody like Doc Girard-Perregaux might be horrified at the idea of living in a mini-auto-apartment ... not realizing that to a pilot it was roomy beyond belief compared to the conning tower of a space craft. His explanation was that a phobia against having his eyes touched prohibited either surgery to remould his eyeballs and cure his myopia, or contact lenses. He was drafted into the working force reserves, served his time, and is now free from toil for the balance of his life. Girard-Perregaux was wagging his finger again, a gesture that, seemingly mild though it was, had an astonishing ability to break off the conversation of one who debated with the easy-seeming, quiet spoken man. If it is admitted that our organization has degenerated to the point that we haven't a single pilot, then it might well be that the Economic Planning Board, and especially those cloddies on Appropriations, will terminate the whole Department of Space Exploration." "Unfortunately, our present-day sailor can't be separated from his money quite so easily.
 It’s the isolation that spacemen feel working alone in space, with only computers as company
 It’s the isolation that spacemen feel working alone in space, with only computers as company  It’s the public’s adverse opinion of space exploration that Gubelin tries to hide.  It’s the desire to return home from a long voyage.  It is the current system of operations for spacecraft, where people man ships with only one person.