Space simulator comprising two chambers carrying a stereoscopic photopair, two light sources carried by a stand and emitting two beams projecting on the two photographs of the photopair the images of the marks, and a stereoscoping viewing device for viewing the two beams. The marks are arranged so that they can be moved exclusively in a stationary plane P.sub.1 conjugated relatively to the lenses of the chambers with a plane P.sub.2 corresponding to the mean position of the photopair.
