But while custom enclosures and super-charged batteries may appeal to the high end of the market, the wealthy are far from the only — or even primary — target. "What we don't want to create is the consummate nerd toy that doesn't have a market outside of Silicon Valley," Eremenko says. The other, more important targets are the 5 billion people who don't yet use a smartphone.

Next year, ATAP hopes to produce what it's calling a "gray phone," a bare-bones device with little more than a processor, Wi-Fi module, and screen. The target Bill of Materials cost would only be $50 (though the retail cost could be higher or lower, depending on Google's largesse or desire for profit). A consumer could buy and use the gray phone, or use an on-phone app to buy module upgrades or custom shells.

"No monolithic phone will ever become a 5-billion-person phone," Eremenko says, but he believes that devices based on the Ara platform could reach that market. That's where the shipping container comes in – it's just one of several different retail experiences the Ara team is considering.

"When this goes to market, this will be the most custom, mass-market product ever created by mankind," Eremenko argues. The closest thing to that level of customization is "maybe Chipotle burritos," he jokes. But the key problem is that when it comes to building out an Ara phone, people will "have to make a huge number of choices that are quite difficult to make, both aesthetic and functional."

Like the modular phone itself, choice is much better in theory than it is in practice. "When presented with choice, if it's not appropriately curated ... or presented to them, they freak out. They tend to get stressed out, they frequently seize up."

To solve the paradox of choice, the Project Ara team is looking into an on-device app, social experiences, and "friend modes" for phones, where users could hand their phone to a friend and let them "clone" their setup as a starting point. They’re also investigating non-invasive biometric scanners that measure your pupil dilation and sweat to see if you're stressed by figuring out all your options (though whether such a system ever becomes reality seems unlikely).

Google will host the store that sells the modules and also will sell the plastic, 3D-printed shells (the latter is because, Eremenko says, the antennas for various modules will have to go into the shell and Google will be responsible for proving to the FCC that they're safe and don't interfere with anything). It will not, however, sell the modules, leaving that to hardware partners. If Project Ara is successful, Google could have a business on its hands that rivals — or even exceeds — Android.

Just as importantly, though, Project Ara could have a ripple effect on the entire mobile industry. One of the goals is to "democratize the hardware ecosystem, break it wide open, basically disintermediate the OEMs," Eremenko says, "so that component developers can now have privy with the consumer."

"Democratize the hardware ecosystem, break it wide open, basically disintermediate the OEMs."

When a component maker, say a camera company or a battery company, wants to get its part into a smartphone, it needs to convince both the factory and the actual smartphone company to include it. But if they can sell the part directly to the consumer — with the help of Ara's design tools to build the module and Google's help to market it — then the Ara ecoystem wouldn’t need giant manufacturers like Foxconn, Pegatron, or even Samsung and HTC to build Android phones. "We want to empower the consumer to make those decisions," Eremenko says, "rather than having the component developer go through an OEM to do that."

It almost goes without saying that Project Ara is wildly ambitious. It’s the sort of thing that typically would involve billions of dollars and multiple years of research and development. Instead ATAP is trying to pull it off with three full-time Google employees, a handful of contractors, and outside companies contributing key parts. And it’s trying to do it all in two years, a seemingly arbitrary deadline that’s just as crazy as the technology itself. "Innovation under time pressure is higher quality innovation," Eremenko argues. "It tends to get rid of red tape, it tends to get rid of dithering, and an inability to make decisions. And it tends to take away risk aversion."

Project Ara — both the proposed phone and the organization trying to create it — is a complicated system. All the pieces have to fit, they have to talk to each other, and they have to all work as promised. That's assuming the modules get produced in the first place, which isn't anything close to a sure bet. But even if all that happens, expect the result to be somewhat inefficient, a little confusing, a tad bulky, and still the most intriguing thing to happen to phones in years.