 The crew was welcomed aboard the ISS by Expedition 34 commander Kevin A. Ford and cosmonauts Evgeny Tarelkin and Oleg Novitskiy.On May 11, 2013, Marshburn and Expedition 35 flight engineer Christopher Cassidy performed an unplanned spacewalk to replace a pump controller box suspected to be the source of an ammonia coolant leak.Marshburn and his crew returned to Earth on May 13, 2013.