Sleep is often poor on the Shuttle, with one survey showing that more than 50% of crewmembers use a hypnotic to sleep at some point in a Shuttle mission. A space mission can also lead to major shifts in circadian rhythms. These are key operational issues, and research on Neurolab will assess how sleep is affected and whether melatonin could be an effective sleep aid in space.
Dr. Charles Czeisler and his colleagues will study melatonin in flight using a double-blind crossover protocol. Sleep will be monitored and fatigue measured using a battery of cognitive tests. Dr. John West and his colleagues will study respiration, and whether changes in the responses to carbon dioxide and oxygen could lead to poor sleep and frequent awakenings.