space equivalent zone en · NOUN
Meanings
- (uncountable) The top of the Earth's atmosphere, from 50,000 ft (the start of the stratosphere) and up (to the edge of the exosphere at 1000 mi); where the effects of exposure to the environment on human life is similar to that of exposure to space; it being physiologically incompatible with human life.
Coordinates
physiological efficient zone · physiological deficient zone (12,500-50,000ft) · space zone (1000mi and up)