Commander Brent Jett (center) talks with employees and visitors at NASA Stennis Space Center. The astronauts of NASA's STS-115 space shuttle mission visited SSC in south Mississippi to share highlights of their 12-day mission and to thank SSC employees for the reliability of the space shuttle's main engines, which helped propel Space Shuttle Atlantis into orbit. STS-115's other crewmembers are (from left) Mission Specialists Joe Tanner, Dan Burbank, Heidemarie Stefanyshyn-Piper and Steve MacLean of the Canadian Space Agency. The mission launched Sept. 9, 2006, resuming construction of the International Space Station.