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Mission or Study ID:   STS-90
Shuttle Program
Launch/Start Date:
Landing/End Date:
16 days
STS-90 Crew Patch

Supported by NASA, international space agencies and domestic partners , the Neurolab mission, which launched on April 17, 1998, was a dedicated 16-day life sciences mission that focused on neuroscience research. Neurolab’s international partners were CSA (Canadian Space Agency), ESA (European Space Agency), CNES (French Space Agency), DARA (German Space Agency) and NASDA (Japanese Space Agency); domestic partners included several institutes at the National Institutes of Health (NIH) including the Division of Research Grants; the National Institute on Aging; the National Institute on Deafness, and other Communication Disorders; National Heart, Lung, and Blood Institute; National Institute on Neurological Disorders and Strokes; and the Office of Naval Research. Neurolab used the orbiting space laboratory called Spacelab, which can be placed in the cargo bay of the Space Shuttle, to conduct life sciences experiments. The orbiter crew included Commander Richard A. Searfoss, Pilot Scott D. Altman, Mission Specialists Richard M. Linnehan, Dafydd Rhys Williams, and Kathryn P. Hire, and Payload Specialists Jay C. Buckey and James A. Pawelczyk. Alternate Payload Specialists were Alexander W. Dunlap and Chiaki Mukai.

The goals and objectives of the Neurolab mission were: 1) to use the unique environment of space flight to study fundamental neurobiological processes; 2) to increase the understanding of the mechanisms responsible for neurologic and behavioral changes that occur in space flight; 3) to further life sciences goals in support of human space flight; and 4) to apply results from space studies to the health, well-being, and economic benefits of people on Earth.

The Neurolab science payload was organized into eight science teams; each principal investigator was assigned to one of these teams. Johnson Space Center monitored the human life sciences teams: Autonomic Nervous System, Sensory Motor and Performance, Sleep and Vestibular, while Ames Research Center monitored the four animal life sciences teams: Aquatic, Adult Neuronal Plasticity, Mammalian Development and Neurobiology.

Autonomic Nervous System investigations studied the effects of microgravity on the autonomic nervous system (ANS), specifically on its role in cardiovascular regulation. In order to monitor the sympathetic response to various ANS stressors and determine the effect of microgravity on the ANS, measurements of muscle sympathetic nerve activity, lower body negative pressure, plasma volume, blood pressure, electrocardiogram (ECG), and metabolite levels were taken.

The Sensory and Performance team examined the effects of space flight on sensory-motor function, performance and perception. Several tests were developed to examine the coordination between vision and motor activity during acclimation to microgravity, the compensation for movement in near-weightlessness, and the after-effects upon return to Earth.

The Sleep investigation team evaluated the normal sleep patterns of crew members before, during and after space flight to identify factors which may contribute to sleep disturbances in space. Sleep experiments were performed to examine whether microgravity contributes to the alterations in sleep patterns. Scientists also investigated the use of melatonin as a hypnotic agent for the treatment of sleep disturbances and the improvement of mood and cognitive performance of the crewmembers.

The Vestibular System is made up of a cavity situated at the entrance to the bony labyrinth in the inner ear which contains the tiny organs governing equilibrium and balance -- the saccule and utricle. This team measured eye movements and perception of astronauts during artificial linear acceleration to determine how spatial orientation of the vestibulo-ocular and optokinetic responses are altered in microgravity.

The Aquatic team studied the afferent and efferent nerve responses of the otoliths in Toadfish in response to linear stimuli, before, during and after space flight. The team also studied the development and formation of the gravity-sensing apparatus in fresh water snails and sword tail fish, both of which underwent significant portions of their embryonic and larval development in flight.

The Adult Neuronal Plasticity Team examined the neural and physiological changes during and following space flight to address the response in the adult Central Nervous System to altered gravity. Three critical areas of neural adaptation were examined: vestibular and motor plasticity, circadian and sleep/wake physiology and anatomy, and homeostatic regulation.

The Mammalian Development team investigated the effects of space flight on the development of the mammalian nervous system. The development of the autonomic nervous system (ANS) and neuromuscular system was carefully studied and measured to determine differences in neurological development in space versus that on Earth.

The Neurobiology team researched the role that gravity plays in specifying the pathways through which nerves send signals throughout the body. Scientists examined the sensory neurons which are controlled by genetic and environmental cues in both the development and regeneration of gravity sensing systems in crickets.

The Neurolab mission encompassed many areas of neuroscience research and allowed in-depth study of several species in space.

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Experiments on this Mission