 Bresnik participated in the first analogue ESA CAVES mission in September 2011, staying underground and exploring the caves for 6 days, simulating Mars mission technologies.On June 10, 2014, NASA announced that Bresnik would command the undersea exploration mission aboard the Aquarius underwater laboratory, which began on September 7, 2014 and lasted seven days.In September 2008 NASA announced that Bresnik was assigned as Mission Specialist STS-129, a shuttle mission to the International Space Station.