DAVID GREENE, HOST:
OK, Renee, this next story we're about to introduce involves some high speed travel and I'm just going a little bit of calculation here. Eight hundred miles an hour. This means I could get from Washington out to you in California in, like, three hours.
RENEE MONTAGNE, HOST:
Hey, we could go to breakfast after the show.
GREENE: I like that idea.
MONTAGNE: Well, this is really rapid transit, though only, you know, it's only a pipe dream for now.
GREENE: But it does involve pipes - or tubes, actually. It's called Hyperloop and passengers would hurl through giant pneumatic tubes really quickly.
MONTAGNE: Which sounds a lot like something from a certain cartoon.
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MONTAGNE: But this is no Saturday morning Jetsons flight of fancy.
GREENE: Yeah. It's a real idea from Elon Musk, the billionaire visionary behind the ecommerce site Paypal, electric car maker Tesla Motors, and the commercial space company Space X. He's described the Hyperloop as a, quote, "cross between a Concord and a rail gun and an air hockey table."
MONTAGNE: Musk unveiled a full proposal on Monday. As NPR's Elise Hu reports, it's not yet clear if or how Hyperloop might actually get built.
ELISE HU, BYLINE: By car it takes at least six hours to drive from Los Angeles to San Francisco. That's without traffic. If the Hyperloop became a reality, its inventor Elon Musk says traveling that distance would take only half an hour.
ELON MUSK: There would be initial acceleration and once you're traveling at speed, you wouldn't notice the speed at all. It would just feel extremely smooth, like you were riding on a cushion of air, really.
HU: The Hyperloop calls for aluminum pods carrying passengers — or even their cars — to be shot through above-ground tubes. It's untested, but Musk's plan combines existing technologies. One: pneumatic tubes that work like giant versions of the chutes you use at drive-thru banks. And two: electromagnets that can propel the pods to their highest speeds.
MARC THOMPSON: I think the devil's in the details, engineering-wise.
HU: Marc Thompson is an engineering consultant and professor of electric engineering at Worcester Polytechnic Institute.
THOMPSON: We don't know yet, whether it would work. It very well may, it might, it probably will. But these things need to be tested and transportation systems are notoriously difficult to get funded, and started and off the ground.
HU: And it's on policy grounds that former U.S. Department of Transportation Assistant Secretary Emil Frankel has reservations.
EMIL FRANKEL: To talk about these kinds of leapfrogging the technology in a context in which we can't really adequately maintain our existing infrastructure is, I think, really not terribly realistic. At least not in terms of the public policy debate.
HU: Musk puts the price tag of this system at about $6 billion. That's a lot of money, but a current proposal for traditional high speed rail in California is more than ten times that. The inspiration for the Hyperloop was Musk's disappointment with that proposal's slow speeds and high cost.
MUSK: That just doesn't seem wise for a state that was facing bankruptcy not that long ago.
HU: For now, the Hyperloop is just a proposal and not even close to a prototype. Musk originally said he just wanted to get the idea out there and not actually build it, since he's so busy. But he said, Monday, he may build a test version.
MUSK: I don't really care much one way or the other if I have any economic outcome here, but it would be cool to see a new form of transport happen.
HU: Cool and garnering a lot of attention. But Musk knows the road to realizing his vision is paved with potential problems.
MUSK: The way these things tend to work is you start building a prototype and you start encountering a whole series of issues that you have to figure out a way around.
HU: Launching a capsule carrying humans in it down a tube will definitely require some testing. Elise Hu, NPR News.
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MONTAGNE: This is NPR News.