ISS038-E-031407 (16 Jan. 2014) --- NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, accesses the Commercial Generic Bioprocessing Apparatus-2 (CGBA-2) while working with the Vaccine-21 Group Activation Pack (GAP) experiment in the Harmony node of the International Space Station. This experiment also referred to as Antibiotic Effectiveness in Space-1 (AES-1) tests the hypothesis that antibiotics used to treat bacterial grown in space will exhibit reduced efficacy and will be associated with specific changes in bacterial gene expression that correlate with cell survival.