On Tuesday morning, space shuttle Discovery will become the first of NASA’s three shuttles — plus a shuttle prototype — to travel to its new retirement home.

NASA flew its last shuttle flight in July. Since then, it’s been prepping the spaceships to become museum displays. And even though the shuttles are headed to places like Los Angeles and New York rather than the space station, figuring out how to get them there has still been a major undertaking.

At daybreak, Discovery will leave Kennedy Space Center in Florida on top of a modified jumbo jet, headed for Washington, D.C. Assuming the weather cooperates, crowds are expected to gather and watch Discovery being flown near the city’s famous monuments.

They’ll see a sight that Jeff Moultrie first saw decades ago. He’s a NASA pilot who will be flying the Boeing 747. NASA has routinely used this shuttle carrier to get its spaceships back to Florida if they had to land at a backup location. Decades ago, when the shuttles were a brand new technological marvel, and long before he ever thought he’d be working for NASA, Moultrie happened to see the shuttle carrier aircraft with the big white spaceship onboard, over Huntsville, Ala.

“It was sort of an image that I’ll probably never forget. And so I think it’s probably the same with most of the folks who are going to be seeing this thing overhead the nation’s capital,” says Moultrie.

Discovery will land at the Dulles International Airport outside Washington, right next to the Steven F. Udvar-Hazy Center of the Smithsonian’s National Air and Space Museum. For years, that facility, full of historic aircraft, has held Enterprise — a prototype shuttle that never flew in space. It will get swapped out for Discovery, since the museum wants a shuttle that was in orbit.

Then, Enterprise heads for its new home. Its turn on NASA’s special 747 will come next week, when it flies to New York City.

The destination is the Intrepid Sea, Air & Space Museum, an aircraft carrier parked on the West Side of Manhattan. To get there from the airport, Enterprise will have to float up the Hudson River on a barge.

“She will be visible. She’s not going to be shrink-wrapped or covered. So when she floats up the river, it’s going to be quite a sight,” says Susan Marenoff-Zausner, president of the Intrepid Museum, who says Enterprise will float by the Statue of Liberty and Ground Zero.

That river trip should happen in June, but the exact timing depends on the tides.

“You don’t want to ground the barge, so you have to wait for a certain level of tide, so that when you’re placing the weight on the barge that the barge remains floating,” explains Marenoff-Zausner. “And then the bridges have a certain clearance, and so we want to wait for the lowest tide to make sure that the shuttle safely clears the bottom of the bridges that we’ll be sailing under.”

A crane will haul Enterprise to the aircraft carrier’s flight deck, where a temporary structure will quickly be erected around it. The museum is still considering its options for permanent display.

Space shuttle Endeavour will be the next to head out, probably in September or October. It’s going to the California Science Center in Los Angeles, which has actually owned Endeavour since last fall.

READ MORE: NPR