Space shuttle Endeavour took off Friday morning on a sightseeing tour of California, the last aerial hurrah before retiring to a Los Angeles museum.

Hitching a ride on top of a jumbo jet, the pair departed Edwards Air Force Base, 100 miles north of Los Angeles, circling the high desert that gave birth to the shuttle fleet before flying north toward Sacramento.

Throngs of spectators were expected to turn out as Endeavour planned low passes over the state Capitol, San Francisco Bay area and several Los Angeles-area landmarks including the Santa Monica Pier, Hollywood Sign and Disneyland.

The nearly 5-hour flyover will culminate with an afternoon landing at the Los Angeles International Airport for an arrival ceremony _ then, in a few weeks, a slow-speed journey across town through neighborhoods to its final museum home.

Since Endeavour will buzz by some of the Golden State's most iconic sights, law enforcement and transportation authorities warned motorists not to "gawk and drive."

"We want people to take in this majestic show," Los Angeles police Cmdr. Scott Kroeber said earlier this week. "But if you're driving, please drive and don't try to take in the show simultaneously."

Extra officers will be on duty along the freeways near the airport to make sure traffic flows smoothly as the shuttle zooms overhead.

Endeavour returned to its birthplace Thursday after an emotional cross-country ferry flight that made a special flyover of Tucson, Ariz., to honor its last commander, Mark Kelly, and his wife, former Arizona Rep. Gabrielle Giffords.

Giffords, who is recovering from a gunshot wound to the head, was "hooting and hollering" as Endeavour looped around her hometown, according to her former aide C.J. Karamargin.

NASA's shuttle fleet, which retired last year after three decades of flight, was assembled in Palmdale near Edwards Air Force Base. The military outpost 100 miles north of Los Angeles served as the original shuttle landing strip and remained a backup site in case of stormy weather at Cape Canaveral, Fla.

"We're so excited to be welcoming Endeavour home in grand style with these flyovers," Jeffrey Rudolph, president of the California Science Center, said earlier this week.

The youngest shuttle, Endeavour replaced Challenger, which blew up during liftoff in 1986. NASA lost another shuttle, Columbia, in 2003 when it disintegrated during re-entry. Fourteen astronauts were killed.

During 25 missions, Endeavour spent 299 days in space and orbited Earth nearly 4,700 times, racking up 123 million miles.

On its maiden flight in 1992, a trio of spacewalking astronauts grabbed a stranded communications satellite in for repair. It also flew the first repair mission to the Hubble Space Telescope to fix a faulty mirror. But most of its flights ferried cargo and equipment to the International Space Station, which is near completion.

Under White House orders to explore beyond low-Earth orbit, NASA is hitching rides on Russian rockets to the orbiting laboratory until private companies can provide regular service.

Endeavour is the second of three remaining shuttles to head to its retirement home. In April, Discovery arrived at the Smithsonian Institution's hangar in Virginia. Atlantis, which closed out the shuttle program, will stay in Florida where it will be towed a short distance to the Kennedy Space Center's visitor center in the fall.

Endeavour will remain at an airport hangar for several weeks as crews ready the shuttle for its own road trip. Unlike Atlantis, it will creep through city streets to the California Science Center near downtown.

Some 400 trees will be cleared along the 12-mile route to make room, a move that has riled some residents in affected neighborhoods. Museum officials have pledged to replant double the number of chopped trees.

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Online:

Shuttle history: http://www.nasa.gov/mission_pages/shuttle

California Science Center: http://www.californiasciencecenter.org

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Alicia Chang can be followed at http://twitter.com/SciWriAlicia