Carla Cioffi / NASA

NASA Administrator Charles Bolden pays a visit to the full-fuselage shuttle trainer, a mockup that found its way from Johnson Space Center to Seattle's Museum of Flight.

NASA Administrator Charles Bolden took a crawl through Memory Lane in Seattle on Tuesday during a tour of the Museum of Flight's shuttle training mockup, which he and hundreds of other astronauts used to practice their moves in preparation for their missions.

"This thing saw astronauts every single day, multiple times a day," Bolden told a small knot of journalists after he climbed in and out of the mockup's plywood cockpit.

It was Bolden's first visit to the full-fuselage trainer since it was flown in pieces from NASA's Johnson Space Center to Seattle aboard a Super Guppy cargo plane last year, and then reassembled for display at the museum's Charles Simonyi Space Gallery. The museum's backers funded the gallery's construction in hopes that NASA would donate one of its three flown shuttles to the museum — but those spacecraft went instead to museums in California, Florida and at the Smithsonian near Washington, D.C.

Seattle's wingless shuttle is one of several mockups that was used to familiarize astronauts with the layout of the actual orbiter. None of the controls actually work, but they're all in the right places, and there's a full-size payload bay that visitors can walk through. For an extra fee, museumgoers can take a "training session" that concludes with a visit to the tight quarters of the crew compartment.

"It's been sold out every weekend," said Doug King, the museum's president and CEO.

Some Seattleites might wish they had a "real" space shuttle in their aerospace-centric city, but Bolden argued that the mockup was a perfect match for the museum.

"I hope I don't get in trouble with any of the other sites, but I think the Museum of Flight won the prize when it comes to education," Bolden said, "because no other place can have somebody essentially walk in the same footsteps that John Glenn, John Young and other people walked when they go through the payload bay, or go up on the flight deck, or go on the middeck. That's actually where we trained. Nobody else is going to be able to do that, even in a flown orbiter."

Bolden is a former shuttle commander who flew on four space missions from 1986 to 1994. He and another retired astronaut, John Creighton, climbed through the mockup's hatch and up the ladder on Tuesday to revisit the cockpit where they spent so many hours preparing for flight — and to reminisce.

Carla Cioffi / NASA

NASA Administrator Charles Bolden reminisces with former astronaut John Creighton on the flight deck of the full-fuselage trainer at Seattle's Museum of Flight. The quarters are so tight that the camera lens shows Creighton in distorted perspective.

Carla Cioffi / NASA

Charles Bolden flashes a smile as he prepares to climb through the hatch of the Museum of Flight's shuttle mockup.

Joe McNally / National Geographic for NASA

Senator-astronaut John Glenn talks with crew trainer Sharon Jones prior to simulating the procedures for escaping from a troubled space shuttle, during a training session at the full-fuselage trainer at Johnson Space Center in 1998.

Bolden pointed to a set of numbered bags hanging by a hatch at the top of the cockpit, and said those bags contained ropes that were thrown through the hatch so that astronauts could practice shimmying down the side of the shuttle. Today, that sounds like an outdated emergency measure — but at the time, it was an essential part of the training.

"The only thing on your mind was, 'Just don't let me fall,'" Bolden said.

The museum also features displays about the commercial successors to the shuttle — as well as a 5-ton rocket prototype donated by Amazon.com billionaire Jeff Bezos' space venture, Blue Origin, which has its headquarters in the Seattle area. During this week's visit to Seattle, Bolden is due to speak to a leadership conference at the Boeing Co., which is working on its own commercial spacecraft capable of carrying astronauts to and from the International Space Station. Bolden said Boeing, Blue Origin and other companies might well create new monuments to spaceflight in the years to come.

"As they begin to fly," Bolden said, "and as many of them meet with success, they'll trade out a display board with an artifact."

Extra credit: Bolden climbed down the ladder from the mockup's flight deck just before I did, and he was kind enough to take hold of my shoe to guide my foot to the first rung of the ladder. This means I'm probably one of the few people in space history to be helped out of a shuttle cockpit by the top guy at NASA. Here's a fuzzy picture I posted to Twitpic, documenting the dubious achievement.

More about space artifacts:

• Shuttle-carrying jet lands in Houston for good
• Shuttle Enterprise's museum reopens after Sandy
• Cosmic Log archive on space history

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Bill Ingalls / NASA

The prototype space shuttle Enterprise is seen mated on top of NASA's modified Boeing 747 Shuttle Carrier Aircraft at Dulles International Airport in Virginia on Friday. Enterprise was the first orbiter built for the space shuttle program, but never went into orbit. It was used primarily for ground and flight tests within the atmosphere. Enterprise had been on display at the Smithsonian National Air and Space Museum's Udvar-Hazy Center in Virginia, but is now being prepared for its new home at the Intrepid Sea Air and Space Museum in New York.

A day after the space shuttle Discovery took its place at the Smithsonian, the prototype shuttle Enterprise is perched on a modified 747 jet for its journey to New York. Now the timing of the trip depends on East Coast weather.

Overnight, Enterprise was towed out to Dulles International Airport and hoisted up into the air with two giant cranes. The jet, known as the Shuttle Carrier Aircraft or SCA, was brought underneath the 75-ton artifact. Then Enterprise was lowered down and "soft-mated" onto the plane at three attach points. The bolts will be tightened down for hard-mating on Saturday, in preparation for the big flight to New York.

This is the same process that Discovery went through in Florida leading up to Tuesday's flight to Dulles for its installation at the Smithsonian National Air and Space Museum's Steven F. Udvar-Hazy Center, next to the airport. On Thursday, Enterprise was moved out of the space it held since the center's opening in 2003, and Discovery was moved in.

NASA had been planning for Enterprise and the SCA to take off from Dulles as early as Monday morning, but this afternoon the space agency said the flight would be delayed due to a forecast of inclement weather in Washington as well as New York. "Managers will continue to review weather forecasts and announce a new flight date as soon as practical," NASA said in its advisory.

When forecasters give the go-ahead, the shuttle-jet combo will head up the East Coast and do a series of New York flyovers. You can expect to see the double-decker behemoth sailing over the Statue of Liberty as well as the Intrepid Sea, Air and Space Museum, the retooled ship where Enterprise will be put on display. After the flyovers, the Enterprise will be set down at New York's John F. Kennedy International Airport.

The shuttle-jet flight is old hat for Enterprise: The craft was the first vehicle built for the space shuttle program, and got its name in part thanks to a write-in campaign by "Star Trek" fans. Unlike the fictional starship, NASA's Enterprise never flew in space. Instead, it was used for ground tests as well as aerodynamic test flights atop the 747 carrier plane. Once the shuttle launches ramped up, Enterprise was deemed no longer needed for testing. It was handed over to the Smithsonian in 1985. The Udvar-Hazy Center's James S. McDonnell Space Hangar was specifically designed to show off the Enterprise.

After the 2003 Columbia tragedy, some sections of the Enterprise's wing panels were removed for impact tests, and those tests made a huge contribution to the accident investigation. That demonstrated that the shuttles can continue to benefit the space program long after their retirement.

It will take a few weeks for Enterprise to settle into its retirement home: The cranes will have to be set up for the shuttle's "demating" at JFK. Then Enterprise will have to be lifted onto a barge and brought up the Hudson River by a tugboat. The schedule calls for Enterprise to be hoisted aboard the Intrepid's flight deck sometime in June. It'll be put on display in a temporary climate-controlled pavilion this summer, and eventually housed in a permanent exhibit facility.

After Enterprise, there's one more shuttle-jet flight on tap: the transfer of Endeavour from NASA's Kennedy Space Center to the California Science Center in Los Angeles. That cross-country trip, due to take place in the latter part of this year, is likely to spark a nationwide frenzy of "Spot the Shuttle" sightings.

The last shuttle that flew in space, Atlantis, is going just down the road to Kennedy Space Center's visitor center, so there'll be no need to bring out the plane for that trip.

For more pictures of the Enterprise-747 mating, check out NASA Headquarters' Flickr gallery. And to get updates on the timing of Enterprise's flight and the flyovers, keep tabs on NASA's website as well as msnbc.com's space news section.

More about the shuttle shuffle:

• Astronauts revisit the shuttle's pros and cons
• How NASA selected the shuttles' future homes
• Seattle gets first pieces of shuttle trainer

Updated 5:20 p.m. ET.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.