NPR: Nell Greenfieldboyce

The final space shuttle mission means that the 30-year-old shuttle program is about to enter the history books alongside the famous Mercury, Gemini, and Apollo programs.

And as the end of the shuttle era looms, NASA leaders say they're about to build a new vehicle, one that will let astronauts go exploring deep into space. But some experts doubt that plan will ever get off the ground.

To understand the big question mark hanging over NASA's future, it helps to first turn the clock back to 2004 — the year after the space shuttle Columbia disaster.

Once space shuttle Atlantis touches down on Earth later this week, workers will start the process of transforming the spaceship into a museum piece.

To see how that mothballing process will unfold, I recently went on a rare tour of Discovery, one of NASA's other shuttles.

Discovery was set up with its landing gear down in a secure hangar at Kennedy Space Center in Florida, where technicians normally do work on the shuttles after each flight.

As space shuttle Atlantis orbits the Earth on NASA's last shuttle mission, it's worth remembering that key parts of this high-tech spaceship were handmade by people back here on Earth.

Five years ago, NPR profiled a few of the workers who make pieces of NASA's shuttles, using everyday tools like sewing needles and X-ACTO knives. With the shuttle program ending, NPR revisited those people to see how their lives are changing now that the shuttles will no longer need them.

If you opened up a copy of the magazine Popular Science back in 1974, you'd see an artist's conception of a blastoff for the new spaceship that NASA was building. The headline: "Reusable Space Shuttle ... Our Biggest Bargain In Out-Of-This-World Research." The era of cheap, routine spaceflight was about to begin.

As hordes of reporters wait for the launch, it's unclear if they'll see a blast off or a lot of rain.

The successor to the Hubble Space Telescope is facing cost overruns and years of delay before it launches, but that hasn't dampened the enthusiasm of scientists who are meeting in Baltimore this week to talk about the amazing research they want to do with the James Webb Space Telescope.

Before space shuttle Atlantis can carry astronauts up on the very last shuttle mission ever, workers on the ground first have to carry Atlantis to the launch pad.

The last shuttle launch is planned for July 8. But the shuttle's final trek to the launch pad is Tuesday night. It's a historic milestone for NASA — and a very personal one for the people in charge of taking the shuttle on this first leg of its final journey.

The space shuttle Endeavour earlier launch was delayed because of technical issues.

Space shuttle Endeavour is scheduled to blast off Friday afternoon on its final mission before becoming a museum exhibit out in California.

President Obama is expected to be there, becoming only the third sitting president to view a human spaceflight launch. Rep. Gabrielle Giffords (D-AZ) will also attend — she was shot in the head earlier this year, but her doctors have OK'd her trip to see her astronaut husband, Commander Mark Kelly, launch into space.

Humpback whales swim in amazingly straight lines during their seasonal migrations that cross thousands of miles of open ocean, and a new study says it's not clear how they're able to chart such a steady course.

"It's just absolutely remarkable how straight these courses are," says Travis Horton, an environmental scientist at the University of Canterbury in New Zealand, who studies animal migrations. "They're doing something rather precise. They're actively and deliberately navigating within some sort of external reference frame."

Terry Button is a fifth-generation farmer from upstate New York who also works as a long-distance trucker, hauling hay and produce up and down the East Coast.

He's proud of his truck and likes it just the way it is. Inside, the cab is homey and low-tech, with a bed behind the two seats and a CB radio. There's no cruise control and no GPS telling him where to go.