The Shuttle Treadmill has been the primary exercise device flown on recent missions. The concern regarding treadmill exercise and its vibration impact on the shuttle mission objectives has necessitated the use of accelerometers to quantify the frequency and magnitude of the vibration during treadmill exercise. This information assisted in designing an isolation device for the treadmill, allowing for the evaluation of alternative exercise devices in terms of the vibration generated, and allowing quantification of the vibration affecting science research. The Space Acceleration Measurement System (SAMS) hardware was used for measuring the levels of vibration.
The purpose of this study was 1) to identify the magnitude and frequency of the vibration generated by the treadmill (during DSO 476 exercise) at the source and on the middeck locker. This determined whether the vibration was amplified or attenuated by the middeck structure and 2) to identify the magnitude and frequency of the vibration generated by other sources of vibration (VRCS, OMS, PRCS, nominal crew activity, and quiescent activity) at the middeck locker. This information was obtained from the SAMS data.
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A familiarization session for the treadmill and bungee restraint system was performed preflight. Prior to the first exercise session in-flight, the SAMS interface cable was taped to the floor near the treadmill. The accelerometer sensor head was affixed to the left side of the treadmill. The frequency and magnitude of the vibration was recorded by the SAMS at the location of the treadmill and at the sensor head placed on a middeck locker door. The crewmembers voice recorded the intensity of the exercise session and the mission elapsed time (MET) of the exercise session. The exercise protocol used the DSO 476 protocol: a 3 minute warm up of walking followed by 10 minutes of running at 60% VO2 max, 10 minutes at 70% VO2 max, 10 minutes at 80% VO2 max, and then 10 minutes of a cool down of walking. Heart rate was monitored. MET of treadmill unstowage and stowage was logged by the crewmembers on a special cue card.
Results for this investigation are unavailable at this time. However, the investigators expected magnitude and frequency of vibration generated by treadmill activity would be periodic and less severe than other sources of vibration (VRCS, OMS, PRCS, nominal crew activity, and quiescent activity) and that vibration levels of the treadmill would be higher during running at 5 mph than walking at 2.5 mph.