ISS012-E-20020 (9 March 2006) --- Astronaut William S. (Bill) McArthur, Expedition 12 commander and NASA space station science officer, works with a portion of the Resistive Exercise Device (RED) in the Destiny laboratory of the International Space Station. In this view, McArthur replaced RED flex packs, which are external splines and spacers that were approaching the end of their certified life.