Crew Exposure Research Articles

Vibroacoustic habitability of space stations

The prediction and control of noise and vibration is essential in the design and operation of future space stations to ensure maximum crew efficiency and utilization. On a number of previous space vehicles, noise and vibration levels have exceeded design specifications and have evoked crew complaints, particularly in the areas of sleep and communication, thus suggesting the need for better vibroacoustic prediction and control techniques. In other cases, adverse reactions have resulted despite design specifications being met which suggests that earth based design criteria may be inadequate for space applications. A technology program is being formulated to develop prediction methods and control techniques for use in the design and operation of space stations to ensure acceptable vibroacoustic levels for bearing, communication, performance, comfort, and sleep. The goals include: accurate vibroacoustic prediction and assessment models for space station design; criteria for assessing the effects of different space station crew exposure levels; and new techniques for controlling the vibroacoustic environment within a space station.

Aircrew Vulnerability in Nuclear Encounters

Abstract : A computational method (algorithm) is described which estimates probable mission outcome resulting from crew exposure to prompt neutron gamma radiation and/or residual fallout radiation. The threat scenario presupposes that:the crew has encountered one or more nuclear weapons; both aircraft and crew have survived the blast and thermal insults; and the aircraft is undegraded by the radiation (aircraft is survivable). Thus one is examining decreases in mission performance based upon crew irradiation only.

Heavy cosmic-ray exposure of Apollo 17 astronauts.

The results of the HZE particle crew dosimetry on Apollo 17 are presented. The measurements are derived from the analysis of 11 passive detectors distributed among the astronauts, the film bag, and a detector located in the Bicore experiment. The individual astronauts' exposure was measured by means of Lexan plastic foils located on the chest, thigh and ankle of each crew member. A mission average planar fluence of 13.4 ± 0.5 particles per cm2 with LET350 > 0.15 MeV/micro in Lexan (LET350 > 130 keV/micro in tissue) was recorded. This represents about a 24 ± 12% increase over the Apollo 16 fluence with the comparison being made between detectors located in similar location. As on earlier missions, significant differences in the recorded HZE exposure were found between the different detectors packets. The Command Module pilot's exposure was found to be measurably lower than those of the Commander and the Lunar Module pilot who received comparable exposures. The exposure at the ankle appears to be consistently higher than that found at the chest or the thigh positions. As before, the highest exposure was recorded by the detectors located in the film bag, while the detectors located in the A6 locker (Biocore experiment) recorded an exposure comparable to the average exposure of the Command Module pilot. These measurements, carried out on the last Apollo mission, confirm the data trend which was steadily emerging in the earlier missions: The HZE particle exposure is sensitive to the shielding environment of the astronauts, including the self shielding of the astronauts bodies, and with the progress of the Apollo program, there has been a gradual, steady increase of the crew exposure.

Cosmic radiation and the Concorde.

One of the environmental problems associated with this high performance supersonic transport aircraft is the exposure of crew and passengers to increased amounts of cosmic radiation, comprising radiations from both galactic and solar sources. As part of the Concorde programme galactic radiation has been measured in commercial subsonic aircraft and in balloons. From these results it is not considered that there will be any risk from exposure to galactic radiation. The problem of intermittent exposure to higher levels from solar activity is outlined, and airborne detection equipment is described, together with suggested ranges for the instrument.