Endeavour's astronauts embarked on the fifth and final spacewalk of their mission Saturday, this time attaching a 50-foot inspection pole to the international space station for use by the next shuttle visitors. Michael Foreman and Robert Behnken floated out the hatch late in the afternoon as the linked shuttle and station soared more than 322 kilometers above the Pacific. They planned to spacewalk the night away. "Spacewalk No. 5 out of five. It's going to be a great one," said their commander, Dominic Gorie. The shuttle astronauts used the laser-tipped inspection boom at the beginning of their 16-day mission and again Friday night to check for any damage to their spaceship. It's become a routine safety procedure ever since the 2003 Columbia accident.