The 122-by-78-foot model will be moved from a warehouse on the Downey Studios lot to a temporary storage tent just north of the Columbia Memorial Space Center.
Downey is throwing a party to celebrate the move with entertainment and activities for children.
The event officially starts at 10 a.m. and the first section should arrive in the tent area around 11 a.m. City officials are holding a special ceremony at noon.
The mock-up, built in 1972, is the ancestor of all the flight-worthy shuttles that were the mainstay of the country’s space program for three decades. The shuttles were built in Downey.
Engineers used the mock-up to design the shuttles. It also served as a marketing tool for Rockwell before the firm won the contract to build the spacecraft.
The city over the next few years plans to work with the Aerospace Legacy Foundation to build an annex structure behind the Space Center, which would serve as a permanent home for the shuttle.
Aerospace Legacy Foundation and city officials hope to eventually repair the shuttle so children can climb around inside.
City officials say an annex structure could cost $2-$3 million, but those familiar with the project said the final cost will likely be substantially more than the city’s estimate.