These crewmembers observed that food which had seemed adequately seasoned prior to flight tasted bland in space. Hygienic facilities in space habitats are still only marginally adequate. When designs reach a higher level of utility it will be possible to evaluate hygienic facilities in terms of more demanding requirements such as acceptability over long durations, ability to support physically active space travelers, etc. Temperature and humidity can also be expected to affect the adjustment to space living. Cold temperatures can influence an individual's ability to perform manipulative tasks as well as cause general discomfort.
High temperatures can result in both decreased performance levels generally and aggressive displays.
Since individuals differ in what they consider acceptable temperatures, space travelers may have to consider temperature preferences along with other features of compatibility. We know that decor assumes more or less importance depending on the conditions of confinement. Although people differ in what they consider desirable, there seems to be an almost universal aversion to environmental uniformity, along with some evidence that, over time, people seek greater complexity in the environment. In the closed environment of space, it will be necessary to test tolerances to both differences and sameness in design. Flexibility is likely to be fundamental to any spacecraft design.