[Amorymeltzer]

Well, 57 isn't really that great of a number by itself. Especially given their exposure to space is relatively transient (compared to, let's say, Earth-based factors) and that you're looking for relatively rare outcomes (like radiation-based issues), 57 is vastly under-powered.

Where the disparity is a real problem, though, is in the matching. You can't just take a random sampling of men and women, you need the populations to match. Think age, race, marriage status, educational achievement, military experience, etc. With so few women, it's hard to get appropriately-matched comparisons. Hence, from the summary:

>Female NASA space station astronauts are on average 2 years younger than male astronauts. While there were no significant differences in the percentage of male (76%) and female space station astronauts (69%) who were married, a significantly greater percentage of male astronauts had at least one child (67% versus 38%) and overall, men had more children than women. From a professional perspective, female NASA space station astronauts have almost twice as many doctorate-level degrees as their male counterparts (50% versus 28%); conversely male NASA space station astronauts had more military experience (73% versus 39%). Sex and gender differences as well as these social determinants could impact adaptation to spaceflight.