ABSTRACT
Until recently, the factors that control ventilation have been essentially unstudied in the microgravity (f.!G) environment. There are likely a number of reasons for this, principal among them being the perception that there was likely to be little change in the control of ventilation in f.!G. In addition, in the early periods of space flight, the cabin atmospheres of the spacecraft differed significantly from that of air breathed at sea level. This change in atmosphere presented such a confounding factor that measures of changes in ventilatory control would be unable to be interpreted in terms of the effect of f.!G per se.
