Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights

• DOI: 10.1152/ajpregu.2001.281.5.r1647
• Publication Date: 2017-12-21T08:15:28Z
• Authors: Derk-Jan Dijk; David F. Neri; James K. Wyatt; Joseph M. Ronda; Eymard Riel; Angela Ritz-De Cecco; Rod J. Hughes; Ann R. Elliott; G. Kim Prisk; John B. West; Charles A. Czeisler
• Keywords: Zeitgeber; Dark therapy; Free-running sleep; Sleep

Sleep, circadian rhythm, and neurobehavioral performance measures were obtained in five astronauts before, during, after 16-day or 10-day space missions. In space, scheduled rest-activity cycles 20–35 min shorter than 24 h. Light-dark highly variable on the flight deck, daytime illuminances other compartments of spacecraft very low (5.0–79.4 lx). amplitude body temperature rhythm was reduced urinary cortisol appeared misaligned relative to imposed non-24-h sleep-wake schedule. Neurobehavioral decrements observed. Sleep duration, assessed by questionnaires actigraphy, only ∼6.5 h/day. Subjective sleep quality diminished. Polysomnography revealed more wakefulness less slow-wave during final third episodes. Administration melatonin (0.3 mg) alternate nights did not improve sleep. After return earth, rapid eye movement (REM) markedly increased. Crewmembers these flights experienced disturbances, loss, performance, postflight changes REM