The 3-minute Psychomotor Vigilance Test (PVT) Self Test (PST) used in the NASA Extreme Environment Mission Operations (NEEMO) 14 and Desert Research and Technology Study (DRATS) analogs, as well as on the International Space Station (ISS), is being developed to help people quickly and objectively detect the extent to which fatigue is affecting their alertness and reaction times. As such, the technology has high potential for usefulness in a range of safety-sensitive environments on Earth. Potentially any occupation in which alertness and fatigue management are essential to prevent errors on critical tasks will benefit from adaptations of the PVT Self Test technology (e.g., airport security screeners, physicians on night shifts and prolonged call). The other two brief cognitive tests evaluated in this project—the Digit Symbol Substitution Test (DSST) and Descending Subtraction Test (DST)—are well validated in the laboratory to be measures of cognitive throughout (DSST) and working memory (DST). These tests have potential to be useful in a range of Earth-based scenarios in which cognitive capability must be rapidly assessed (e.g., sedation, mild to moderate traumatic brain injury, mild cognitive impairment with aging).