LOS ANGELES - The space shuttle Endeavour, bolted to the top of a jumbo jet, was to take off on Friday from Edwards Air Force Base for a last airborne victory lap over California en route to its final frontier and retirement home - a science museum in Los Angeles.
Riding piggyback on a specially modified Boeing 747, the 75-ton winged spaceship was scheduled to depart at 8:15 a.m. Pacific time (11.15am local time) on the final leg of its cross-country trip that started on Wednesday in Cape Canaveral, Florida. The scheduled departure was about an hour later than originally planned due to fog over the San Francisco Bay area.
After making at least 20 planned low-altitude passes over some of California's best-known landmarks and scientific institutions, including Disneyland and the Jet Propulsion Laboratory, Endeavour and its carrier jet are expected to land at Los Angeles International Airport at about 12:45 p.m. local time (3.45am local time).
Friday's flight from Edwards, about 100 miles (160 km) north of Los Angeles in the Mojave Desert, will mark Endeavour's last ferry flight, and the final airborne journey for any of NASA's three surviving shuttles.
NASA retired Endeavour and the rest of its shuttle fleet last year after completing the US portion of the $100 billion (S$1.2 billion) International Space Station, a permanently staffed research complex orbiting 250 miles (400 km) above Earth.
Its arrival Thursday afternoon at Edwards was a homecoming of sorts for the California-made spacecraft, which was built as a replacement for Challenger, the shuttle lost in a 1986 launch accident that killed seven astronauts.
Endeavour went on to fly 25 missions, including 12 to help construct and outfit the space station, and logged nearly 123 million miles (198 million km) in flight during 4,671 orbits.
Seven of those missions ended with Endeavour landing at Edwards, which served as NASA's principal backup for shuttle returns during much of the 30-year orbiter program in case of bad weather over Cape Canaveral.