S118-E-09283 (18 Aug. 2007) --- Canadian Space Agency's astronaut Dave Williams (right), and astronaut Rick Mastracchio (left), both STS-118 mission specialists, along with Charlie Hobaugh (left, partially out of frame), pilot, work on the middeck of Space Shuttle Endeavour as the crew prepares for their return home. Hatches were closed between the International Space Station and Endeavour at 4:10 p.m. on Aug. 18.