Space shuttle Endeavour completes its retirement trip Friday NASA delays Endeavour's Friday California flight tour to avoid fog Former shuttle commander Mark Kelly, former U.S. Rep. Gabby Giffords saw flyover Thursday The retired shuttle is headed toward a museum in Los Angeles (CNN) -- Endeavour will do flyovers Friday of Los Angeles, Sacramento and San Francisco atop a modified jumbo jet -- weather permitting -- then land back at Los Angeles International Airport to end its three-day journey to its retirement home. Good visibility is key, since the purpose of the flight up the state of California and back is to show off Endeavour to the American public from the sky, and NASA encourages onlookers to share their sightings of the airborne spectacle on social media. NASA delayed Friday's takeoff by an hour to 8:15 a.m. PDT "to increase the probability that fog over the San Francisco area will dissipate before the flyover," according to the space agency's website. After its day trip is done, the orbiter will be removed from its perch atop the Boeing 747 that has carried it cross-country from Florida's Kennedy Space Center. Its final destination is the California Science Center in Los Angeles, where it will go on display for posterity. NASA said the shuttle will be moved via roads on October 12-13 to its final spot at the science museum. On Thursday, it flew low over Tucson, Arizona, where Mark Kelly, who was the commander on the last Endeavour mission, watched with his wife, former U.S. Rep. Gabby Giffords, before touching down at Edwards Air Force Base in California. "The space shuttle is really a testament to American engineering and ingenuity," he told CNN affiliate KOLD. It is the most amazing spacecraft ever built, by far. His wife had watched the launch of his mission but missed the landing, so it was great for her to see the shuttle in the air, he added. Endeavour's three-day piggyback flight was divided into three legs that could be described as scenic routes to showcase the shuttle to the public from coast to coast. Social media users have shared Endeavour sightings via the hashtags #spottheshuttle and #OV105, the later being Endeavour's "vehicle designation." As Endeavour bid farewell to Kennedy Space Center, it elicited strong emotions from people -- such as CNN iReporter Randy Lathrop of Cocoa, Florida -- who have lived with the shuttle program nearby for decades. This is her home," Lathrop said. Named for the first ship commanded by British explorer James Cook, Endeavour rolled out of an assembly plant in Palmdale, California, in 1991 at a cost of $1.7 billion.