A happy ''thumbs up'' from the crew of the Space Shuttle Endeavour and NASA Dryden Flight Research Center officials heralded the successful completion of mission STS-100. Standing by the shuttle's rocket nozzles from left to right: Scott E. Prazynski, mission specialist (U.S.); Yuri V. Lonchakov, mission specialist (Russia); Kent V. Rominger, commander (U.S.); Wally Sawyer, NASA Dryden Flight Research Center deputy director; Kevin Petersen, NASA Dryden Flight Research Center director; Umberto Guidoni, mission specialist (European Space Agency); John L. Phillips, mission specialist (U.S.); Jeffrey S. Ashby, pilot (U.S.); and Chris A. Hadfield, mission specialist (Canadian Space Agency). The mission landed at Edwards Air Force Base, California, on May 1, 2001.