S134-E-006436 (17 May 20110) --- NASA astronauts Greg Chamitoff (left), mission specialist, and Mark Kelly, mission commander, work on separate chores on Endeavour's middeck during the second flight day of the STS-134 mission. Chamitoff is holding Cube Lab Module ? 8. Kelly is unpacking canisters of the Group Activation Pack. Endeavour and its crew of six astronauts will arrive at the International Space Station in less than 24 hours. Photo credit: NASA