(CBS News) NEW YORK - The space shuttle program is history. One by one, the orbiters are making their final journeys to museums -- hitching rides on top of a 747.
It got CBS News wondering, how do they do that? CBS News national correspondent Chip Reid took a look.
It was a stunning sight as the Space Shuttle Discovery soared piggy-back over the National Mall and the Enterprise over New York City, each on top of a specially modified Boeing 747.
Ray Zink, a NASA contractor, has been putting shuttles on top of jumbo jets for 14 years. We caught up with him at the Intrepid Museum in Manhattan, where the Enterprise will soon find a home. Reid asked what Zink thought when he first heard they were going to put the orbiter on the back of a 747.
"First off, you don't think it's possible," Zink said. "You just look at the sheer size and the drag, and you're like, 'It can't be done.'"
Zink has supervised the coupling more than 40 times. It takes place in a massive 10-story steel structure: a 10- to 12-hour process where the shuttle, with its fragile coating of heat resistant tiles, is delicately placed in a sling, then slowly lifted. The 747 is moved underneath, and the shuttle is then lowered into place and secured with just three large bolts.
"It's amazingly solid," Zink assured. "If you can imagine, the three attach points where the shuttle is mounted to the 747 are the exact same three attach points where it mounts to the external tank during launch. It's bolted on pretty well. It's not ever going to fall off."
This weekend Zink supervised the off-loading of Enterprise at John F. Kennedy Airport in New York. But, there's no steel tower there, so he used two heavy-lift cranes, one weighing more than a million pounds.
If watching a shuttle on top of a 747 is awe-inspiring, imagine what it's like to fly it.
Jeff Moultrie was the pilot over Washington and the co-pilot over New York.
"That was a great flight," Moultrie said. "The first thing you see, even from a distance, is the Statue of Liberty, and to be able to go over that and to basically own New York for a period of maybe 45 minutes."
But the flying contraption has its downsides.
"With a shuttle on board, the handling characteristics and the drag factor are vastly changed," Moultrie said.
Vibration can be extreme, and while the 747 is stripped bare on the inside to reduce weight, takeoff can be a nail-biter with the plane carrying 704,000 pounds -- very close to its 710,000-pound maximum.
Both Moultrie and Zink are still amazed it gets off the ground at all.
"As many times as you see it, you still stand back and go, 'Is it going to make it? It is going to make it?'" Zink said.
"Like there it goes," Zink added, turning his head as if he was watching the shuttle and plane go by. "It's unbelievable. You're like, 'I can't believe it.'"
He'll get to believe it one more time in September when the 747 carries the Endevour to a museum in California, the last time a shuttle will ever leave the ground.