On its launch mission in 1992, the spacecraft’s crew snared and redeployed a stranded satellite, and the next year it serviced the Hubble Space Telescope.

When it embarks on its epic final journey Tuesday, departing the Kennedy Space Centre in Florida to travel by air and road to its new home at the California Science Centre in Los Angeles, many shuttle enthusiasts may argue that the Endeavour is undertaking its most memorable trip ever.

On Friday, the fifth and final space shuttle to be built was attached atop Nasa’s modified 747 Shuttle Carrier Aircraft in a final preparation for the journey.

Once Endeavour is on display, the last vestige of the three-decade shuttle programme will be permanently retired.

Without the shuttles, US space agency Nasa is now relying on Russian Soyuz capsules to ferry astronauts to the International Space Station. Private companies are working to win Nasa contracts to fly supplies and eventually people to the ISS, and in May Space X’s Dragon capsule made the first commercial cargo delivery to the orbiting laboratory.

Meanwhile, Nasa has turned its focus to a new spacecraft to travel beyond low-Earth orbit with eventual goals including an asteroid and Mars.

Endeavour and its 747 will take to the skies on Tuesday morning, after the planned Monday start was postponed due to weather, Nasa announced, in an echo of a common occurrence during the now-retired orbiter’s working life. Shuttle blastoffs were often postponed when weather was unfavourable at Cape Canaveral, Florida.

During four final days of flights, the spacecraft will conduct low-level flyovers across the US — flying as low as just 500 metres above numerous locations along the flight path.

The extraordinary sight will take the mother plane and its historic cargo swooping over the Kennedy Space Centre and Cape Canaveral, the launch pads of so many space missions.

The aircraft will fly low over New Orleans and Houston. Other cities where residents can hope to see the spectacular flyovers are San Francisco and Sacramento. But residents of Los Angeles will have the best view of all, when the shuttle and its carrier plane conduct a series of flyovers of Los Angeles before landing there.

Huge crowds are expected to turn out to see the retiring symbol of the US space programme.

When Nasa delivered the shuttle Discovery to the Smithsonian Museum outside Washington, traffic was snarled for hours.

It’s a fitting finale for the Endeavour after 18 years in service, during which it flew almost 200 million kilometres and spent 299 days in space.

Named after the ship sailed by Captain James Cook on his first voyage of discovery, the spaceship has special significance for Nasa as it was built to replace the Challenger, which blew up after takeoff in 1986.

Nasa was encouraging people on the flight path to report their sightings on special Twitter feeds using the hashtags #spottheshuttle and #OV105, Endeavour’s orbiter vehicle designation.

The journey will not end when Endeavour gets to Los Angeles International Airport. In fact in some ways it is proving to be the most awkward stage of the journey.

The huge spacecraft, with its 26-metre wingspan and 20-metre tail is too big to get through freeway bridges. The 77-tonne orbiter is too heavy to go by helicopter.

It therefore has to travel on the back of a special transporter truck through a circuitous, 20-kilometre route through South Los Angeles and Inglewood. Crews have been busy for weeks along the shuttle’s path, clearing 400 trees from roadways and sidewalks to make room for the behemoth.

“They are cutting down these really big, majestic trees,” Lark Galloway-Gilliam, a longtime resident and neighborhood council director, told the Los Angeles Times. “It will be beyond my lifetime before they will be tall like this again.”  The California Science Centre has said it would replant twice as many trees along the route to replace the greenery that will be chopped down.

“(Endeavour) is a historical artifact and national treasure,” science centre chief Jeffrey Rudolph said. “The community understands that and recognizes that it will help inspire the next generation of explorers.”