Engineering topics

Thornton, W.

Publications and source records attributed to Thornton, W..

6 records

NASA NTRS1993

Ambulatory blood pressure and heart rate during shuttle flight, entry and landing

Ambulatory blood pressures (BP) and heart rates (HR) were recorded on a series of early Shuttle flights during preflight and pre-entry, entry, landing and egress. There were no significant differences between flight and preflight values during routine activity. Systolic blood pressure was slightly elevated in the deorbit period and systolic and diastolic blood pressure and heart rates were all elevated with onset of gravitoinertial loads and remained so through egress. Two of seven subjects had orthostatic problems in egress but their data did not show significant differences from others except in heart rate. Comparison of this data to that from recent studies show even larger increase in HR/BP values during current deorbit and entry phases which is consistent with increased heat and weight loads imposed by added survival gear. Both value and limitations of ambulatory heart rate/blood pressure data in this situation are demonstrated.

Thornton, W.↗

NASA NTRS1993

A complex reaction time study (Sternberg) in space flight

Simple and complex (Sternberg) reaction time studies were flown on three and seven day Shuttle flights in 1985. Three subjects did selftesting with an onboard handheld calculator without difficulty. There was little change in simple reaction time. One subject demonstrated a decrease in the processing rate during space motion sickness while a second exhibited an increase in complex reaction time without a change in processing rate during a period of high work load. The population was too small to demonstrate significant changes. This study demonstrates the ease and practicality of such measurements and indicates the potential value of such studies in space.

Thornton, W.↗

NASA NTRS1992

Shock and vibration isolation for cyclic exercise in spacecraft

A unique feature of undisturbed space flight is vibration and weight free environments not available on Earth. On long flights, exercise and especially locomotor exercise will be required if the crew is to function in a relatively normal fashion and avoid lengthy rehabilitation on return to Earth. Exercise forces in the low frequency range can amount to 2 to 3 times crew body weight in the frequency range most critical to material science. Therefore, the amount of isolation will need to be orders of magnitude greater than present techniques. The following is a brief rationale of the need for these exercises and a description of exercise forces. Current isolation means and their deficiencies will be described, and a method capable of providing the isolation proposed and work to date will be mentioned.

Thornton, W.↗

NASA NTRS1991

Flight test of an improved solid waste collection system

A system for human waste collection is described and evaluated on the basis of a prototype employed for the shuttle flight STS-35. The manually operated version of the unit is designed to collect, compact, and store human waste and cleaning material in replaceable volumes. The system is presented with illustrations and descriptions of the disposable pads that are used to clean the cylinder and occlusive air valves as well as seal the unit. Temporary retention and waste entrainment are provided by the variable airflow in the manual unit tested. The prototype testing indicates that sufficient airflow is achieved at 45 CFM and that the stowage volume (18.7 cu in.) is adequate for storing human waste with minimal logistical support. Higher compaction pressure and the use of a directed airstream are proposed for improving the packing efficiency of the unit.

Thornton, W.↗

NASA NTRS1991

Locomotor exercise in weightlessness

The requirements for exercise in space by means of locomotion are established and addressed with prototype treadmills for use during long-duration spaceflight. The adaptation of the human body to microgravity is described in terms of 1-G locomotor biomechanics, the effects of reduced activity, and effective activity-replacement techniques. The treadmill is introduced as a complement to other techniques of force replacement with reference given to the angle required for exercise. A motor-driven unit is proposed that can operate at a variety of controlled speeds and equivalent grades. The treadmills permit locomotor exercise as required for long-duration space travel to sustain locomotor and cardiorespiratory capacity at a level consistent with postflight needs.

Thornton, W.↗

NASA NTRS1975

Physiological mass measurements on Skylab 1/2 and 1/3

Mass measurements of crewmen and objects were made for the first time in space during Skylab. A description of the new devices designed for such measurements and of the technique of their use is detailed. Results from ground-based chamber simulation tests and from those during Skylab II and III show similar patterns of simple metabolic deficits, of a rapid loss during the first few days of flight followed by a reciprocal gain for the first few postflight days, and other transient changes. It is concluded that two major causes of weight loss are present: (1) a fluid redistribution and loss, and (2) metabolic losses. Added to these are short-term changes from transient stress. Smaller, simpler, and cheaper devices have since been designed which should allow mass measurements on virtually any object in almost any spacecraft.

Thornton, W.↗