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| Mission Brief |
We'd like to thank the American
Society for Gravitational and Space Biology for this Mission Brief.
In 1983 an historic space event took place -- the first
Spacelab flight. The international Spacelab took up where Skylab
left off and offered the promise of major new scientific advances. Three
major life science flights: Spacelab
Life Sciences-1 (SLS-1
or STS-40, flown in 1991), SLS-2
(STS-58, flown in 1993) and LMS
(STS-78, flown in 1996) have contributed much to our knowledge of adaptation
to spaceflight. Neurolab
may well be the last of this series and the last Spacelab flight. The experiments,
procedures and testing planned for Neurolab
show how much progress has been made since Spacelab-1.
The physiologic challenges of spaceflight remain unchanged
since Spacelab-1 days. Motion sickness remains a significant, but now treatable,
problem inflight. Crewmembers return with difficulties in maintaining balance.
Standing upright after spaceflight can be difficult due both to labile
blood pressure and unstable posture. Muscle mass and strength are reduced.
Astronauts tend to sleep poorly. Many of these symptoms reflect major
underlying changes in the nervous system. This has led to a series
of questions that will be answered on Neurolab. For example,
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How has the information from gravity sensors (such as the
inner ear) been reinterpreted?
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Has nervous control of the circulation been altered? How
have circadian rhythms been affected?
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What neural plasticity is there and how does it work?
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Can the quality and quantity of sleep be improved?
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Does spaceflight change the way blood pressure and brain
blood flow is regulated?
Neurolab will study both people and experimental animals
to find answers -- recording everything from the crewmember's ability to
catch a ball, to changes in gene expression in the rat brain. Particularly
important is a new series investigations in the area of mammalian neural
development, which ask the following:
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Is gravity necessary for normal development?
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How do muscles and their neural connections develop without
gravity?
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Will the vestibular system develop normally?
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Are there critical periods in development when gravity is
essential?
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Will animals walk properly if these skills develop in space?
These are basic questions about nervous system development
that can only be performed without gravity, and Neurolab will provide the
needed environment.
The 26 Neurolab Experiments have been organized into teams,
each focusing on a particular area. The eight teams are:
The experiments in each team share resources to answer the
different questions addressed by each investigator. We hope that
what may be the last Spacelab flight will also be the most productive!