HOUSTON, Aug. 18 (UPI) -- The countdown started Saturday to see which would reach the United States first -- the space shuttle Endeavour or Hurricane Dean.
NASA said Mission Control in Houston had given the crew a "go" for undocking the shuttle from the International Space Station at 8 a.m. EDT Sunday. The decision makes it possible to bring Endeavour and its crew home Tuesday, should Dean threaten the Houston area and force Mission Control to shut down to prepare for the storm, NASA said.
Mission managers will continue to evaluate weather forecasts and adjust the shuttle's schedule as needed.
To accommodate an early departure, astronauts Dave Williams and Clay Anderson finished the mission's shortened fourth spacewalk in just over five hours, and the hatches were closed at 5:10 p.m. Saturday, NASA said. During their out-of-shuttle experience, Williams and Anderson installed a stand for the shuttle’s robotic arm extension boom on the station’s truss structure, installed an antenna and retrieved two experiment containers.
U.S. astronauts spent a total of 23 hours and 15 minutes floating outside the shuttle and space station on this mission. Saturday's final walk was the 92nd devoted to space station assembly, NASA said.