The Effects of Training on Anxiety and Task Performance in Simulated Suborbital Spaceflight

INTRODUCTION: In commercial spaceflight, anxiety could become mission-impacting, causing negative experiences or endangering the flight itself. We studied layperson response to four varied-length training programs (ranging from 1 h-2 d of preparation) prior to centrifuge simulation of launch and re-entry acceleration profiles expected during suborbital spaceflight. We examined subject task execution, evaluating performance in high-stress conditions. We sought to identify any trends in demographics, hemodynamics, or similar factors in subjects with the highest anxiety or poorest tolerance of the experience. METHODS: Volunteers participated in one of four centrifuge training programs of varied complexity and duration, culminating in two simulated suborbital spaceflights. At most, subjects underwent seven centrifuge runs over 2 d, including two +G(z) runs (peak +3.5 G(z), Run 2) and two +G(x) runs (peak +6.0 G(x), Run 4) followed by three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z), peak +6.0 G(x) and +4.0 G(z)). Two cohorts also received dedicated anxiety mitigation training. Subjects were evaluated on their performance on various tasks, including a simulated emergency. RESULTS: Participating in 2-7 centrifuge exposures were 148 subjects (105 men, 43 women, age range 19-72 yr, mean 39.4 +/- 13.2 yr, body mass index range 17.3-38.1, mean 25.1 +/- 3.7). There were 10 subjects who withdrew or limited their G exposure; history of motion sickness was associated with opting out. Shorter length training programs were associated with elevated hemodynamic responses. Single-directional G training did not significantly improve tolerance. DISCUSSION: Training programs appear best when high fidelity and sequential exposures may improve tolerance of physical/psychological flight stressors. The studied variables did not predict anxiety-related responses to these centrifuge profiles.