Table 1.

Demographics and flight experience for 6-month astronauts^a

	6-month astronauts (n = 10) b
Sexc	9 males; 1 female
Age at baseline scan, mean (SD), yearsd	48 (6)
Number of flight days this mission, mean (SD), days	162 (25)
Naïve or experienced flyer	6 naïve; 4 experienced
Number of previous missions, mean (SD), number of missions	0.7 (1.0)
Number of previous flight days, mean (SD), number of flights	57 (115)
Intermission timee, mean (SD), days	2009 (270)
Intermission timee, mean (SD), years	5.5 (0.7)

^aIndividual data are not presented here for the 12-month astronauts to protect their privacy. Both of the 12-month astronauts gave permission for their brain data to be depicted in this work as single subject results.

^b n = 10 in each case, except for intermission time where n = 4 because six of the 6-month astronauts were naïve flyers.

^cOne of the 12-month astronauts was male, and the other was female.

^dBoth of the 12-month astronauts fell within 2 standard deviations of the mean age of the 6-month astronauts.

^eIntermission time is calculated as the time from the previous flight’s landing day to the launch day of the present flight.