Authors: James W Swan; Paula A Vasquez; Peggy A Whitson; E Michael Fincke; Koichi Wakata; Sandra H Magnus; Frank De Winne; Michael R Barratt; Juan H Agui; Robert D Green; Nancy R Hall; Donna Y Bohman; Charles T Bunnell; Alice P Gast; Eric M Furst Journal: Proc Natl Acad Sci U S A Date: 2012-09-17 Impact factor: 11.205