 The STS-95 mission launched in October of 1998. Its seven-member crew
performed a number of duties, including a variety of science experiments carried in the pressurized Spacehab
module, the deployment and retrieval of the Spartan free-flyer payload, and operations with the HST Orbiting
Systems Test (HOST) and the International Extreme Ultraviolet Hitchhiker (IEH) payloads carried in the payload
bay.
The UCSD team, in collaboration with a group from Brigham and Women's Hospital at the
Harvard Medical School, did a study of sleep on orbit, in a sleep experiment similar to that flown on
Neurolab. Two subjects were instrumented for sleep with EEG, EOG, and EMG electrodes
in a "sleep net," and wore the RIP Suit and harness, which provided respiratory
movement, ECG, sound, light, pulse oximetry, and nasal air flow. All signals were recorded on the
Digital Sleep Recorder. Body core temperature was measured constantly throughout the
flight, and the subjects' cognitive performance was tested on days following instrumented sleep to see how the
quality of sleep that the astronauts got affected their performance the next day. The subjects participated in
experiment sessions before, during, and after the mission, and acted as their own controls.
An additional scientific study being performed as part of the sleep study on STS-95 is the
study of aging, with John Glenn being one of the participants in the sleep experiment. Certain physiological
changes that occur in space also occur with aging: cardiovascular deconditioning, balance disorders, weakening
bones and muscles, a depressed immune response, as well as disturbed sleep. An important difference, however, is
that these changes are reversible in astronauts. The change in sleep pattern that typically comes with aging is
early waking and fragmented or otherwise disturbed sleep. Optimal alertness during the day and sound sleep at
night, valuable qualities on Earth and in space, require proper synchronizing of the human circadian pacemaker.
Thus, we seek to better understand how aging and space flight affect the mechanisms governing circadian rhythms.
For more information about the STS-95 mission, please see these pages:
You may also visit our
Photo Gallery to see pictures of our activities during STS-95 training and baseline data collection. |
