NASA / REUTERS NASA's Mars rover Curiosity is pictured in a handout self-portrait, Feb. 3, 2013.

Here’s a bit of news you’ve surely not heard: in 17 years, a colony of 80,000 humans is going to be living on Mars! They’ll be joining a smaller community that will arrive in 2023—a group that will be grateful for the company since their mission will be only one way. And all of them will be preceded by a team of astronauts who will swing by the Red Planet and fly back home just five years from now.

On the way, they’ll see some remarkable things: tourists popping into space on suborbital flights, courtesy of Richard Branson’s Virgin Galactic joyrides; other paying travelers heading for inflatable orbital hotels; miners heading out to grapple asteroids and bring their riches (iron! platinum! gold!) back to Earth; NASA astronauts hanging in space at the mysterious Lagrange points, where gravity from the moon, Earth and sun cancel one another out allowing spacecraft simply to hover.

All of this, to hear the visionaries tell it, is coming soon. Or maybe not—since all of it, to hear the cynics tell it, is doomed to fail. Either way, when it comes to space, something new and faintly unhinged is clearly going on.

(MORE: TIME’s Complete SXSW Coverage)

If nature abhors a vacuum, the same is true of the aerospace community, and for more than half a century, that vacuum was comfortably filled. In the U.S., NASA was the only space-player around, and in the rest of the world, it was at least the biggest. The unmanned program came first, then the Mercury, Gemini and Apollo programs, and then from 1972 to 2011, the shuttle and International Space Station (ISS) programs. Most of the money, most of the talent and nearly all of the innovation was commanded from NASA headquarters in Washington. And then, suddenly, much of it went away.

With the mothballing of the shuttles, the completion of the space station and the Obama administration’s decision to turn all manned travel to low Earth orbit over to the private sector, the innovators have finally bestirred themselves—rushing into the void with money, ideas and their own teams of young engineers and expat NASA employees, only too happy to pick up where the once-great space agency left off. So far, their prospects are decidedly mixed. On Tuesday, at South by Southwest, Time will consider all of this with the help of a panel of three folks who know a thing or two about the space game: Mike Griffin, administrator of NASA from 2005 to 2009; Marsha Ivins, a retired—and decidedly plainspoken—astronaut who is a veteran of five shuttle flights; and Sara Seagar, MIT astrophysicist and planetary scientist specializing in the hunt for exoplanets, and an adviser for Planetary Resources, the newly announced asteroid mining company.

For both experts and lay space observers, it’s the most harebrained ideas that draw the most attention, simply because they’re also the most sensational. This week, for example, Bas Lansdorp, a Dutch engineer, announced plans to raise $6 billion to launch an open-ended, years-long reality show that will follow a crop of candidate astronauts as they apply to be the first settlers on Mars, go through their training and then set out on their journey sometime around 2023—with no system in place to bring them back. They will, instead, be the space equivalent of the sailors who arrive on an island and burn their boats, settling the land rather than visiting it.

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“This will be one of the biggest events in human history. We are talking about creating a major media spectacle,” he told the New York Times, which inexplicably led the front page of its business section in its March 9 edition with coverage of Lansdorp and his fever dream.

More modest, if slightly more credible, is Dennis Tito’s plan to raise money for a circum-Mars flyby and get the thing off the ground by 2018. Tito’s space resume has just a single line on it: he is a multimillionaire who, in 2001 he paid $20 to fly as a tourist aboard the ISS for just under eight days. His Mars plan, he says, would cost about $2 billion. Both he and Lansdorp assume the technology to fly the missions pretty much exists (it doesn’t) and that they can figure out the human factors—how to shield astronauts from cosmic rays and keep them healthy and sane on a years-long mission, for starters—in just the short time frame they’ve allowed themselves to do it (they can’t).

Far more credible are the plans being put forward by Elon Musk, founder of PayPal, Tesla Motors and SpaceX, who at least has a proven track record, building real rockets and a real orbital spacecraft that have done real work—twice completing successful resupply missions to the space station. But Musk gets ahead of himself too: the 80,000-person Mars colony is his plan, based on his belief that economies of scale can work the same way in space that they do on Earth, and that he can ultimately reduce his costs per passenger to about $500,000—cut-rate coach seats by space standards, but exponentially cheaper than anything anyone’s been able to achieve before.

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Bigelow Aerospace, based out of Las Vegas and headed by entrepreneur Robert Bigelow, has some cred too—at least enough that NASA has tentatively signed onto the idea of the company adding one or two of its still-in-development inflatable modules to the ISS. But building a habitable, orbital B&B for rich space tourists, then putting them through the years of training they’d need to take their vacations, presents another whole order of difficulty.

That is the problem with all of the new proposals: they are more about idea than execution. Know how hard it is to drop even a small manned spacecraft through the atmosphere and get it safely back to Earth? Now imagine grappling a platinum asteroid and somehow bringing that back home—not to mention what it would do to the economics of platinum in the first place, which is valuable as an investment metal precisely because it’s so rare. The Lagrange points sound like a wonderfully eerie place to visit and it’s one of the possible targets the Obama White House has proposed for future deep space missions by NASA. But what do you do when you get there except, well, hang around?

Time’s SXSW experts will hardly have all the answers, but they’re the kinds of people who will be needed to come up with them—people who know the field, who trained in the field and who can temper vision with a knowledge of what might actually work. Time.com will be reporting on what they have to say, but here’s betting they won’t be setting their DVR’s for Lansdorp’s reality show anytime soon.

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