After completing 25 missions and logging 122.9 million flight miles, the space shuttle Endeavour swooped low over Vandenberg Air Force Base on Friday morning in its final leg of a cross-country victory lap before retiring to the California Science Center in downtown Los Angeles. The 75-ton spaceship piggybacked atop a modified Boeing 747 and marked the final airborne journey for any of NASA’s three surviving shuttles. Endeavour was built as a replacement for the Challenger shuttle and made 12 trips to help build the International Space Station. Named after Captain James Cook’s HMS Endeavour, it first flew in 1992 and had its last mission in 2011.