The Rive Brothers used to be like a technology gang. In the late 1990s, they would jump on skateboards and zip around the streets of Santa Cruz, knocking on the doors of businesses and asking if they needed any help managing their computing systems. The young men, who had all grown up in South Africa with their cousin Elon Musk, soon decided there must be an easier way to hawk their technology smarts than going door-to-door. They wrote some software that allowed them to take control of their clients' systems from afar and to automate many of the standard tasks that companies required, such as installing updates for applications. The software became the basis of a new company called Everdream, and the brothers promoted their technology in some compelling ways. Billboards went up around Silicon Valley in which Lyndon Rive, a buff underwater hockey player, stood naked with his pants around his ankles, while holding a computer in front of his crotch. Up above his photo, the tagline for the ad read, "Don't get caught with your systems down."

After arriving at Burning Man, Musk, a regular at the event, and his family went through their standard routines. They set up camp and prepped their art car for a drive. This year, they had cut the roof off a small car, elevated the steering wheel, shifted it to the right so that it was placed near the middle of the vehicle, and replaced the seats with a couch. Musk took a lot of pleasure in driving the funky creation. "Elon likes to see the rawness of people there," said Bill Lee, his longtime friend. "It's his version of camping. He wants to go and drive the art cars and see installations and the great light shows. He dances a lot." Musk put on a display of strength and determination at the event as well. There was a wooden pole perhaps thirty feet high with a dancing platform at the top. Dozens of people tried and failed to climb it, and then Musk gave it a go. "His technique was very awkward, and he should not have succeeded," said Lyndon. "But he hugged it and just inched up and inched up until he reached the top."

By 2004, Lyndon and his brothers, Peter and Russ, wanted a new challenge -- something that not only made them money but, as Lyndon put it, "something that made us feel good every single day." Near the end of the summer that year, Lyndon rented an RV and set out with Musk for the Black Rock desert and the madness of Burning Man. The men used to go on adventures all the time when they were kids and looked forward to the long drive as a way to catch up and brainstorm about their businesses. Musk knew that Lyndon and his brothers were angling for something big. While driving, Musk turned to Lyndon and suggested that he look into the solar energy market. Musk had studied it a bit and thought there were some opportunities that others had missed. "He said it was a good place to get into," Lyndon recalled.

Musk and the Rives left Burning Man enthused. The Rives decided to become experts on the solar industry and find the opportunity in the market. They spent two years studying solar technology and the dynamics of the business, reading research reports, interviewing people, and attending conferences along the way. It was during the Solar Power International conference that the Rive brothers really hit on what their business model might be. Only about two thousand people showed up for the event, and they all fit into a couple of hotel conference rooms for presentations and panels. During one open discussion session, representatives from a handful of the world's largest solar installers were sitting onstage, and the moderator asked what they were doing to make solar panels more affordable for consumers. "They all gave the same answer," Lyndon said. "They said, 'We're waiting for the cost of the panels to drop.' None of them were taking ownership of the problem."

At the time, it was not easy for consumers to get solar panels on their houses. You had to be very proactive, acquiring the panels and finding someone else to install them. The consumer paid up front and had to make an educated guess as to whether or not his or her house even got enough sunshine to make the ordeal worthwhile. On top of all this, people were reluctant to buy panels, knowing that the next year's models would be more efficient.

The Rives decided to make buying into the solar proposition much simpler and formed a company called SolarCity in 2006. Unlike other companies, they would not manufacture their own solar panels. Instead they would buy them and then do just about everything else in-house. They built software for analyzing a customer's current energy bill and the position of their house and the amount of sunlight it typically received to determine if solar made sense for the property. They built up their own teams to install the solar panels. And they created a financing system in which the customer did not need to pay anything up front for the panels. The consumer leased the panels over a number of years at a fixed monthly rate. Consumers got a lower bill overall, they were no longer subject to the constantly rising rates of typical utilities, and, if they sold their house, they could pass the contract to the new owner. At the end of the lease, the homeowner could also upgrade to new, more efficient panels. Musk had helped his cousins come up with this structure and become the company's chairman and its largest shareholder, owning about a third of SolarCity.

During the entire period of SolarCity's growth, Silicon Valley had dumped huge amounts of money into green technology companies with mostly disastrous results. There were the automotive flubs like Fisker and Better Place, and Solyndra, the solar cell maker that conservatives loved to hold up as a cautionary tale of government spending and cronyism run amok. Some of the most famous venture capitalists in history, like John Doerr and Vinod Khosla, were ripped apart by the local and national press for their failed green investments. The story was almost always the same. People had thrown money at green technology because it seemed like the right thing to do, not because it made business sense. From new kinds of energy storage systems to electric cars and solar panels, the technology never quite lived up to its billing and required too much government funding and too many incentives to create a viable market. Much of this criticism was fair. It's just that there was this Elon Musk guy hanging around who seemed to have figured something out that everyone else had missed. "We had a blanket rule against investing in clean-tech companies for about a decade," said Peter Thiel, the PayPal cofounder and venture capitalist at Founders Fund. "On the macro level, we were right because clean tech as a sector was quite bad. But on the micro level, it looks like Elon has the two most successful clean-tech companies in the U. S. We would rather explain his success as being a fluke. There's the whole Iron Man thing in which he's presented as a cartoonish businessman -- this very unusual animal at the zoo. But there is now a degree to which you have to ask whether his success is an indictment on the rest of us who have been working on much more incremental things. To the extent that the world still doubts Elon, I think it's a reflection on the insanity of the world and not on the supposed insanity of Elon."

Six years later, SolarCity had become the largest installer of solar panels in the country. The company had lived up to its initial goals and made installing the panels painless. Rivals were rushing to mimic its business model. SolarCity had benefited along the way from a collapse in the price of solar panels, which occurred after Chinese panel manufacturers flooded the market with product. It had also expanded its business from consumers to businesses with companies like Intel, Walgreens, and Wal-Mart signing up for large installations. In 2012, SolarCity went public and its shares soared higher in the months that followed. By 2014, SolarCity was valued at close to $7 billion.

Starting in 2014, SolarCity began to make the full extent of its ambitions more obvious. First, the company began selling energy storage systems. These units were built through a partnership with Tesla Motors. Battery packs were manufactured at the Tesla factory and stacked inside refrigerator-sized metal cases. Businesses and consumers could purchase these storage systems to augment their solar panel arrays. Once they were charged up, the battery units could be used to help large customers get through the night or during unexpected outages. Customers could also pull from the batteries instead of the grid during peak energy use periods, when utilities tend to tack on extra charges. While SolarCity rolled the storage units out in a modest, experimental fashion, the company expects most of its customers to buy the systems in the years ahead to smooth out the solar experience and help people and businesses leave the electrical grid altogether.

SolarCity, like the rest of Musk's ventures, did not represent a business opportunity so much as it represented a worldview. Musk had decided long ago -- in his very rational manner -- that solar made sense. Enough solar energy hits the Earth's surface in about an hour to equal a year's worth of worldwide energy consumption from all sources put together. Improvements in the efficiency of solar panels have been happening at a steady clip. If solar is destined to be mankind's preferred energy source in the future, then this future ought to be brought about as quickly as possible.

Then, in June 2014, SolarCity acquired a solar cell maker called Silevo for $200 million. This deal marked a huge shift in strategy. SolarCity would no longer buy its solar panels. It would make them at a factory in New York State. Silevo's cells were said to be 18.5 percent efficient at turning light into energy, compared to 14.5 percent for most cells, and the expectations were that the company could reach 24 percent efficiency with the right manufacturing techniques. Buying, rather than manufacturing, solar panels had been one of SolarCity's great advantages. It could capitalize on the glut in the solar cell market and avoid the large capital expenditures tied to building and running factories. With 110,000 customers, however, SolarCity had started to consume so many solar panels that it needed to ensure a consistent supply and price. "We are currently installing more solar than most of the companies are manufacturing," said Peter Rive, the cofounder and chief technology officer at SolarCity. "If we do the manufacturing ourselves and take advantage of some different technology, our costs will be lower -- and this business has always been about lowering the costs."

What's more, SolarCity is a key part of what can be thought of as the unified field theory of Musk. Each one of his businesses is interconnected in the short term and the long term. Tesla makes battery packs that SolarCity can then sell to end customers. SolarCity supplies Tesla's charging stations with solar panels, helping Tesla to provide free recharging to its drivers. Newly minted Model S owners regularly opt to begin living the Musk Lifestyle and outfit their homes with solar panels. Tesla and SpaceX help each other as well. They exchange knowledge around materials, manufacturing techniques, and the intricacies of operating factories that build so much stuff from the ground up.

After adding the leases, the storage units, and the solar cell manufacturing together, it became clear to close observers of SolarCity that the company had morphed into something resembling a utility. It had built out a network of solar systems all under its control and managed by the company's software. By the end of 2015, SolarCity expects to have installed 2 gigawatts' worth of solar panels, producing 2.8 terawatt-hours of electricity per year. "This would put us on a path to fulfill our goal to become one of the largest suppliers of electricity in the United States," the company said after announcing these figures in a quarterly earnings statement. The reality is that SolarCity accounts for a tiny fraction of the United States' annual energy consumption and has a long way to go to become a major supplier of electricity in the country. There can, however, be little doubt that Musk intends for the company to be a dominant force in the solar industry and in the energy industry overall.

As of 2012, Musk Co. turned into a real threat, and it became harder to go at SolarCity, Tesla, or SpaceX as individual companies. Musk's star power had surged and washed over all three ventures at the same time. When Tesla's shares jumped, quite often SolarCity's did, too. Similar optimistic feelings accompanied successful SpaceX launches. They proved Musk knew how to accomplish the most difficult of things, and investors seemed to buy in more to the risks Musk took with his other enterprises. The executives and lobbyists of aerospace, energy, and automotive companies were suddenly going up against a rising star of big business -- an industrialist celebrity. Some of Musk's opponents started to fear being on the wrong side of history or at least the wrong side of his glow. Others began playing really dirty.

For most of their histories, SolarCity, Tesla, and SpaceX have been the clear underdogs in their respective markets and gone to war against deep-pocketed, entrenched competitors. The solar, automotive, and aerospace industries remain larded down by regulation and bureaucracy, which favors incumbents. To people in these industries Musk came off as a wide-eyed technologist who could be easily dismissed and ridiculed and who, as a competitor, fell somewhere on the spectrum between annoying and full of shit. The incumbents did their usual thing using their connections in Washington to make life as miserable as possible on all three of Musk's companies, and they were pretty good at it.

Musk has spent years buttering up the Democrats. He's visited the White House several times and has the ear of President Obama. Musk, however, is not a blind loyalist. He first and foremost backs the beliefs behind Musk Co. and then uses any pragmatic means at his disposal to advance his cause. Musk plays the part of the ruthless industrialist with a fierce capitalist streak better than most Republicans and has the credentials to back it up and earn support. The politicians in states like Alabama looking to protect some factory jobs for Lockheed or in New Jersey trying to help out the automobile dealership lobby now have to contend with a guy who has an employment and manufacturing empire spread across the entire United States. As of this writing, SpaceX had a factory in Los Angeles, a rocket test facility in central Texas, and had just started construction on a spaceport in South Texas. (SpaceX does a lot of business at existing launch sites in California and Florida, as well.) Tesla had its car factory in Silicon Valley, the design center in Los Angeles, and had started construction on a battery factory in Nevada. (Politicians from Nevada, Texas, California, New Mexico, and Arizona threw themselves at Musk over the battery factory, with Nevada ultimately winning the business by offering Tesla $1.4 billion in incentives. This event confirmed not only Musk's soaring celebrity but also his unmatched ability to raise funds.) SolarCity has created thousands of white- and blue-collar clean-tech jobs, and it will create manufacturing jobs at the solar panel factory that's being built in Buffalo, New York. All together, Musk Co. employed about fifteen thousand people at the end of 2014. Far from stopping there, the plan for Musk Co. calls for tens of thousands of more jobs to be created on the back of ever more ambitious products.

Tesla's primary focus throughout 2015 will be bringing the Model X to market. Musk expects the SUV to sell at least as well as the Model S and wants Tesla's factories to be capable of making 100,000 cars per year by the end of 2015 to keep up with demand for both vehicles. The major downside accompanying the Model X is its price. The SUV will start at the same lofty prices as the Model S, which limits the potential customer base. The hope, though, is that the Model X turns into the luxury vehicle of choice for families and solidifies the Tesla brand's connection with women. Musk has pledged that the Supercharger network, service centers, and the battery-swap stations will be built out even more in 2015 to greet the arrival of the new vehicle. Beyond the Model X, Tesla has started work on the second version of the Roadster, talked about making a truck, and, in all seriousness, has begun modeling a type of submarine car that could transition from road to water. Musk paid $1 million for the Lotus Esprit that Roger Moore drove underwater in The Spy Who Loved Me and wants to prove that such a vehicle can be done. "Maybe we'll make two or three, but it wouldn't be more than that," Musk told the Independent newspaper. "I think the market for submarine cars is quite small."

Tesla already consumes a huge portion of the world's lithium ion battery supply and will need far more batteries to produce the Model 3. This is why, in 2014, Musk announced plans to build what he dubbed the Gigafactory, or the world's largest lithium ion manufacturing facility. Each Gigafactory will employ about 6,500 people and help Tesla meet a variety of goals. It should first allow Tesla to keep up with the battery demand created by its cars and the storage units sold by SolarCity. Tesla also expects to be able to lower the costs of its batteries while improving their energy density. It will build the Gigafactory in conjunction with longtime battery partner Panasonic, but it will be Tesla that is running the factory and fine-tuning its operations. According to Straubel, the battery packs coming out of the Gigafactory should be dramatically cheaper and better than the ones built today, allowing Tesla not only to hit the $35,000 price target for the Model 3 but also to pave the way for electric vehicles with 500-plus miles of range.

At the opposite end of the sales spectrum, or so Musk hopes, will be Tesla's third-generation car, or the Model 3. Due out in 2017, this four-door car would come in around $35,000 and be the real measure of Tesla's impact on the world. The company hopes to sell hundreds of thousands of the Model 3 and make electric cars truly mainstream. For comparison, BMW sells about 300,000 Minis and 500,000 of its BMW 3 Series vehicles per year. Tesla would look to match those figures. "I think Tesla is going to make a lot of cars," Musk said. "If we continue on the current growth rate, I think Tesla will be one of the most valuable companies in the world."

In early 2014, Tesla raised $2 billion by selling bonds. Tesla's ability to raise money from eager investors was a newfound luxury. Tesla had bordered on bankruptcy for much of its existence and been one major technical gaffe from obsolescence at all times. The money coupled with Tesla's still-rising share price and strong sales has put the company in a position to open lots of new stores and service centers while advancing its manufacturing capabilities. "We don't necessarily need all of the money for the Gigafactory right now, but I decided to raise it in advance because you never know when there will be some bloody meltdown," Musk said. "There could be external factors or there could be some unexpected recall and then suddenly we need to raise money on top of dealing with that. I feel a bit like my grandmother. She lived through the Great Depression and some real hard times. Once you've been through that, it stays with you for a long time. I'm not sure it ever leaves really. So, I do feel joy now, but there's still that nagging feeling that it might all go away. Even later in life when my grandmother knew there was really no possibility of her going hungry, she always had this thing about food. With Tesla, I decided to raise a huge amount of money just in case something terrible happens."

If Tesla actually can deliver an affordable car with 500 miles of range, it will have built what many people in the auto industry insisted for years was impossible. To do that while also constructing a worldwide network of free charging stations, revamping the way cars are sold, and revolutionizing automotive technology would be an exceptional feat in the history of capitalism.

Musk felt optimistic enough about Tesla's future to talk to me about some of his more whimsical plans. He hopes to redesign the Tesla headquarters in Palo Alto, a change employees would welcome. The building, with its tiny, 1980s-era lobby and a kitchen that can barely handle a few people making cereal at the same time, has none of the perks of a typical Silicon Valley darling. "I think our Tesla headquarters looks like crap," Musk said. "We're going to spruce things up. Not to sort of the Google level. You have to be like making money hand over fist in order to be able to spend money the way that Google does. But we're going to make our headquarters much nicer and put in a restaurant." Naturally, Musk had ideas for some mechanical enhancements as well. "Everybody around here has slides in their lobbies," he said. "I'm actually wondering about putting in a roller coaster -- like a functional roller coaster at the factory in Fremont. You'd get in, and it would take you around factory but also up and down. Who else has a roller coaster? I'm thinking about doing that with SpaceX, too. That one might be even bigger since SpaceX has like ten buildings now. It would probably be really expensive, but I like the idea of it."

What's fascinating is that Musk remains willing to lose it all. He doesn't want to build just one Gigafactory but several. And he needs these facilities to be built quickly and flawlessly, so that they're cranking out massive quantities of batteries right as the Model 3 arrives. If need be, Musk will build a second Gigafactory to compete with the Nevada site and place his own employees in competition with each other in a race to make the batteries first. "We're not really trying to sort of yank anyone's chain here," Musk said. "It's just like this thing needs to be completed on time. If we suddenly find that we're leveling the ground and laying the foundation and we're on a bloody Indian burial ground, then fuck. We can't say, 'Oh shit. Let's go back to the other place that we were thinking about and get a six-month reset.' Six months for this factory is a huge deal. Do the basic math and it's more than a billion dollars a month in lost revenue, assuming we use it to capacity. From a different standpoint, if we spend all the money to prepare the car factory in Fremont to triple the volume from 150,000 per year to 450,000 or 500,000 cars and hire and train all the people, and we're just sitting there waiting for the factory to come on line, we'd be burning money like it was going out of fashion. I think that could kill the company.

"The competitors are all sort of pooh-poohing the Gigafactory," Musk said. "They think it's a stupid idea, that the battery supplier should just go build something like that. But I know all the suppliers, and I can tell you that they don't like the idea of spending several billion dollars on a battery factory. You've got a chicken-and-egg problem where the car companies are not going to commit to a giant volume because they're not sure you can sell enough electric cars. So, I know we can't get enough lithium ion batteries unless we build this bloody factory, and I know no one else is building this thing."

"A six-month offset would be like, like Gallipoli. You have to make sure you charge right after the bombardment. Don't fucking sit around for two hours so that the Turks can go back in the trenches. Timing is important. We have to do everything we can to minimize the timing risk."

What Musk struggles to fathom is why other automakers with deeper pockets aren't making similar moves. At a minimum, Tesla seems to have influenced consumers and the auto industry enough for there to be an expected surge in demand for electric vehicles. "I think we have moved the needle for almost every car company," Musk said. "Just the twenty-two thousand cars we sold in 2013 had a highly leveraged effect in pushing the industry toward sustainable technology." It's true that the supply for lithium ion batteries is already constrained, and Tesla looks like the only company addressing the problem in a meaningful way.

There's the potential that Tesla is setting itself up to capitalize on a situation like the one Apple found itself in when it first introduced the iPhone. Apple's rivals spent the initial year after the iPhone's release dismissing the product. Once it became clear Apple had a hit, the competitors had to catch up. Even with the device right in their hands, it took companies like HTC and Samsung years to produce anything comparable. Other once-great companies like Nokia and BlackBerry didn't withstand the shock. If, and it's a big if, Tesla's Model 3 turned into a massive hit -- the thing that everyone with enough money wanted because buying something else would just be paying for the past -- then the rival automakers would be in a terrible bind. Most of the car companies dabbling in electric vehicles continue to buy bulky, off-the-shelf batteries rather than developing their own technology. No matter how much they wanted to respond to the Model 3, the automakers would need years to come up with a real challenger and even then they might not have a ready supply of batteries for their vehicles.

"I think it is going to be a bit like that," Musk said. "When will the first non-Tesla Gigafactory get built? Probably no sooner than six years from now. The big car companies are so derivative. They want to see it work somewhere else before they will approve the project and move forward. They're probably more like seven years away. But I hope I'm wrong."

Musk speaks about the cars, solar panels, and batteries with such passion that it's easy to forget they are more or less sideline projects. He believes in the technologies to the extent that he thinks they're the right things to pursue for the betterment of mankind. They've also brought him fame and fortune. Musk's ultimate goal, though, remains turning humans into an interplanetary species. This may sound silly to some, but there can be no doubt that this is Musk's raison d'être. Musk has decided that man's survival depends on setting up another colony on another planet and that he should dedicate his life to making this happen.

Musk is now quite rich on paper. He was worth about $10 billion at the time of this writing. When he started SpaceX more than a decade ago, however, he had far less capital at his disposal. He didn't have the fuck-you money of a Jeff Bezos, who handed his space company Blue Origin a kingly pile of cash and asked it to make Bezos's dreams come true. If Musk wanted to get to Mars, he would have to earn it by building SpaceX into a real business. This all seems to have worked in Musk's favor. SpaceX has learned to make cheap and effective rockets and to push the limits of aerospace technology.

In the near term, SpaceX will begin testing its ability to take people into space. It wants to perform a manned test flight by 2016 and to fly astronauts to the International Space Station for NASA the next year. The company will also likely make a major move into building and selling satellites, which would mark an expansion into one of the most lucrative parts of the aerospace business. Along with these efforts, SpaceX has been testing the Falcon Heavy -- its giant rocket capable of flying the biggest payloads in the world -- and its reusable-rocket technology. In early 2015, SpaceX almost managed to land the first stage of its rocket on a platform in the ocean. Once it succeeds, it will begin performing tests on land.

In 2014, SpaceX also began construction on its own spaceport in South Texas. It has acquired dozens of acres where it plans to construct a modern rocket launch facility unlike anything the world has seen. Musk wants to automate a great deal of the launch process, so that the rockets can be refueled, stood up, and fired on their own with computers handling the safety procedures. SpaceX wants to fly rockets several times a month for its business, and having its own spaceport should help speed up such capabilities. Getting to Mars will require an even more impressive set of skills and technology.

"And then I think for each flight that departs to Mars you want to sort of launch the spacecraft into orbit and then have it be in a parking orbit and refuel its tanks with propellant. Essentially, the spacecraft would use a bunch of its propellant to get to orbit, but then you send up a tanker spacecraft to fill up the propellant tanks of the spacecraft so that it can depart for Mars at high speed and can do so and get there in three months instead of six months and with a large payload. I don't have a detailed plan for Mars but I know of something at least that would work, which is sort of this all-methane system with a big booster, a spacecraft, and a tanker potentially. I think SpaceX will have developed a booster and spaceship in the 2025 time frame capable of taking large quantities of people and cargo to Mars.

"We need to figure out how to launch multiple times a day," Musk said. "The thing that's important in the long run is establishing a self-sustaining base on Mars. In order for that to work -- in order to have a self-sustaining city on Mars -- there would need to be millions of tons of equipment and probably millions of people. So how many launches is that? Well, if you send up 100 people at a time, which is a lot to go on such a long journey, you'd need to do 10,000 flights to get to a million people. So 10,000 flights over what period of time? Given that you can only really depart for Mars once every two years, that means you would need like forty or fifty years.

"Eventually, you'd need to heat Mars up if you want it to be an Earthlike planet, and I don't have a plan for that. That would take a long time in the best of circumstances. It would probably take, I don't know, somewhere between a century and a millennium. There's zero chance of it being terraformed and Earthlike in my lifetime. Not zero, but 0.001 percent chance, and you would have to take real drastic measures with Mars."

"The thing that's important is to reach an economic threshold around the cost per person for a trip to Mars. If it costs $1 billion per person, there will be no Mars colony. At around $1 million or $500,000 per person, I think it's highly likely that there will be a self-sustaining Martian colony. There will be enough people interested who will sell their stuff on Earth and move. It's not about tourism. It's like people coming to America back in the New World days. You move, get a job there, and make things work. If you solve the transport problem, it's not that hard to make a pressurized transparent greenhouse to live in. But if you can't get there in the first place, it doesn't matter.

Musk spent months pacing around his home in Los Angeles late at night thinking about these plans for Mars and bouncing them off Riley, whom he remarried near the end of 2012. "I mean, there aren't that many people you can talk to about this sort of thing," Musk said. These chats included Musk daydreaming aloud about becoming the first man to set foot on the Red Planet. "He definitely wants to be the first man on Mars," Riley said. "I have begged him not to be." Perhaps Musk enjoys teasing his wife or maybe he's playing coy, but he denied this ambition during one of our late-night chats. "I would only be on the first trip to Mars if I was confident that SpaceX would be fine if I die," he said. "I'd like to go, but I don't have to go. The point is not about me visiting Mars but about enabling large numbers of people to go to the planet." Musk may not even go into space. He does not plan to participate in SpaceX's upcoming human test flights. "I don't think that would be wise," he said. "It would be like the head of Boeing being a test pilot for a new plane. It's not the right thing for SpaceX or the future of space exploration. I might be on there if it's been flying for three or four years. Honestly, if I never go to space, that will be okay. The point is to maximize the probable life span of humanity."

It's difficult to gauge just how seriously the average person takes Musk when he talks like this. A few years ago, most people would have lumped him into the category of people who hype up jet packs and robots and whatever else Silicon Valley decided to fixate on for the moment. Then Musk filed away one accomplishment after another, transforming himself from big talker to one of Silicon Valley's most revered doers. Thiel has watched Musk go through this maturation -- from the driven but insecure CEO of PayPal to a confident CEO who commands the respect of thousands. "I think there are ways he has dramatically improved over time," said Thiel. Most impressive to Thiel has been Musk's ability to find bright, ambitious people and lure them to his companies. "He has the most talented people in the aerospace industry working for him, and the same case can be made for Tesla, where, if you're a talented mechanical engineer who likes building cars, then you're going to Tesla because it's probably the only company in the U. S. where you can do interesting new things. Both companies were designed with this vision of motivating a critical mass of talented people to work on inspiring things." Thiel thinks Musk's goal of getting humans to Mars should be taken seriously and believes it gives the public hope. Not everyone will identify with the mission but the fact that there's someone out there pushing exploration and our technical abilities to their limits is important. "The goal of sending a man to Mars is so much more inspiring than what other people are trying to do in space," Thiel said. "It's this going-back-to-the-future idea. There's been this long wind-down of the space program, and people have abandoned the optimistic visions of the future that we had in the early 1970s. SpaceX shows there is a way toward bringing back that future. There's great value in what Elon is doing."

The true believers came out in full force in August 2013 when Musk unveiled something called the Hyperloop. Billed as a new mode of transportation, this machine was a large-scale pneumatic tube like the ones used to send mail around offices. Musk proposed linking cities like Los Angeles and San Francisco via an elevated version of this kind of tube that would transport people and cars in pods. Similar ideas had been proposed before, but Musk's creation had some unique elements. He called for the tube to run under low pressure and for the pods to float on a bed of air produced by skis at their base. Each pod would be thrust forward by an electromagnetic pulse, and motors placed throughout the tube would give the pods added boosts as needed. These mechanisms could keep the pods going at 800 mph, allowing someone to travel from Los Angeles to San Francisco in about thirty minutes. The whole thing would, of course, be solar-powered and aimed at linking cities less than a thousand miles apart. "It makes sense for things like L. A. to San Francisco, New York to D. C., New York to Boston," Musk said at the time. "Over one thousand miles, the tube cost starts to become prohibitive, and you don't want tubes every which way. You don't want to live in Tube Land."

Musk had been thinking about the Hyperloop for a number of months, describing it to friends in private. The first time he talked about it to anyone outside of his inner circle was during one of our interviews. Musk told me that the idea originated out of his hatred for California's proposed high-speed rail system. "The sixty-billion-dollar bullet train they're proposing in California would be the slowest bullet train in the world at the highest cost per mile," Musk said. "They're going for records in all the wrong ways." California's high-speed rail is meant to allow people to go from Los Angeles to San Francisco in about two and a half hours upon its completion in -- wait for it --2029. It takes about an hour to fly between the cities today and five hours to drive, placing the train right in the zone of mediocrity, which particularly gnawed at Musk. He insisted the Hyperloop would cost about $6 billion to $10 billion, go faster than a plane, and let people drive their cars onto a pod and drive out into a new city.

Musk's tune, however, started to change after he released the paper detailing the Hyperloop. Bloomberg Businessweek had the first story on it, and the magazine's Web server began melting down as people stormed the website to read about the invention. Twitter went nuts as well. About an hour after Musk released the information, he held a conference call to talk about the Hyperloop, and somewhere in between our numerous earlier chats and that moment, he'd decided to build the thing, telling reporters that he would consider making at least a prototype to prove that the technology could work. Some people had their fun with all of this. "Billionaire unveils imaginary space train," teased Valleywag. "We love Elon Musk's nutso determination -- there was certainly a time when electric cars and private space flight seemed silly, too. But what's sillier is treating this as anything other than a very rich man's wild imagination." Unlike its early Tesla-bashing days, Valleywag was now the minority voice. People seemed mainly to believe Musk could do it. The depth to which people believed it, I think, surprised Musk and forced him to commit to the prototype. In a weird life-imitating-art moment, Musk really had become the closest thing the world had to Tony Stark, and he could not let his adoring public down.

At the time, it seemed that Musk had dished out the Hyperloop proposal just to make the public and legislators rethink the high-speed train. He didn't actually intend to build the thing. It was more that he wanted to show people that more creative ideas were out there for things that might actually solve problems and push the state forward. With any luck, the high-speed rail would be canceled. Musk said as much to me during a series of e-mails and phone calls leading up to the announcement. "Down the road, I might fund or advise on a Hyperloop project, but right now I can't take my eye off the ball at either SpaceX or Tesla," he wrote.

Shortly after the release of the Hyperloop plans, Shervin Pishevar, an investor and friend of Musk's, brought the detailed specifications for the technology with him during a ninety-minute meeting with President Obama at the White House. "The president fell in love with the idea," Pishevar said. The president's staff studied the documents and arranged a one-on-one with Musk and Obama in April 2014. Since then, Pishevar, Kevin Brogan, and others, have formed a company called Hyperloop Technologies Inc. with the hopes of building the first leg of the Hyperloop between Los Angeles and Las Vegas. In theory, people would be able to hop between the two cities in about ten minutes. Nevada senator Harry Reid has been briefed on the idea as well, and efforts are under way to buy the land rights alongside Interstate 15 that would make the high-speed transport possible.

For employees like Gwynne Shotwell and J. B. Straubel, working with Musk means helping develop these sorts of wonderful technologies in relative obscurity. They're the steady hands that will forever be expected to stay in the shadows. Shotwell has been a consistent presence at SpaceX almost since day one, pushing the company forward and suppressing her ego to ensure that Musk gets all the attention he desires. If you're Shotwell and truly believe in the cause of sending people to Mars, then the mission takes precedence over personal desires. Straubel, likewise, has been the constant at Tesla -- a go-between whom other employees could rely on to carry messages to Musk, and the guy who knows everything about the cars. Despite his stature at the company, Straubel was one of several longtime employees who confessed they were nervous to speak with me on the record. Musk likes to be the guy talking on his companies' behalf and comes down hard on even his most loyal executives if they say something deemed to be out of line with Musk's views or with what he wants the public to think. Straubel has dedicated himself to making electric cars and didn't want some dumb reporter wrecking his life's work. "I try really hard to back away and put my ego aside," Straubel said. "Elon is incredibly difficult to work for, but it's mostly because he's so passionate. He can be impatient and say, 'God damn it! This is what we have to do!' and some people will get shell-shocked and catatonic. It seems like people can get afraid of him and paralyzed in a weird way. I try to help everyone to understand what his goals and visions are, and then I have a bunch of my own goals, too, and make sure we're in synch. Then, I try and go back and make sure the company is aligned. Ultimately, Elon is the boss. He has driven this thing with his blood, sweat, and tears. He has risked more than anyone else. I respect the hell out of what he has done. It just could not work without Elon. In my view, he has earned the right to be the front person for this thing."

The communications departments of SpaceX and Tesla have witnessed the latter forms of behavior more than any other group of employees. Musk has burned through public relations staffers with comical efficiency. He tends to take on a lot of the communications work himself, writing news releases and contacting the press as he sees fit. Quite often, Musk does not let his communications staff in on his agenda. Ahead of the Hyperloop announcement, for example, his representatives were sending me e-mails to find out the time and date for the press conference. On other occasions, reporters have received an alert about a teleconference with Musk just minutes before it started. This was not a function of the PR people being incompetent in getting word of the event out. The truth was that Musk had only let them know about his plans a couple of minutes in advance, and they were scrambling to catch up to his whims. When Musk does delegate work to the communications staff, they're expected to jump in without missing a beat and to execute at the highest level. Some of this staff, operating under this mix of pressure and surprise, only lasted between a few weeks and a few months. A few others have hung on for a couple of years before burning out or being fired.

The rank-and-file employees tend to describe Musk in more mixed ways. They revere his drive and respect how demanding he can be. They also think he can be hard to the point of mean and come off as capricious. The employees want to be close to Musk, but they also fear that he'll suddenly change his mind about something and that every interaction with him is an opportunity to be fired. "Elon's worst trait by far, in my opinion, is a complete lack of loyalty or human connection," said one former employee. "Many of us worked tirelessly for him for years and were tossed to the curb like a piece of litter without a second thought. Maybe it was calculated to keep the rest of the workforce on their toes and scared; maybe he was just able to detach from human connection to a remarkable degree. What was clear is that people who worked for him were like ammunition: used for a specific purpose until exhausted and discarded."

The granddaddy example of Musk's seemingly callous interoffice style occurred in early 2014 when he fired Mary Beth Brown. To describe her as a loyal executive assistant would be grossly inadequate. Brown often felt like an extension of Musk -- the one being who crossed over into all of his worlds. For more than a decade, she gave up her life for Musk, traipsing back and forth between Los Angeles and Silicon Valley every week, while working late into the night and on weekends. Brown went to Musk and asked that she be compensated on par with SpaceX's top executives, since she was handling so much of Musk's scheduling across two companies, doing public relations work and often making business decisions. Musk replied that Brown should take a couple of weeks off, and he would take on her duties and gauge how hard they were. When Brown returned, Musk let her know that he didn't need her anymore, and he asked Shotwell's assistant to begin scheduling his meetings. Brown, still loyal and hurt, didn't want to discuss any of this with me. Musk said that she had become too comfortable speaking on his behalf and that, frankly, she needed a life. Other people grumbled that Brown and Riley clashed and that this was the root cause of Brown's ouster. (Brown declined to be interviewed for this book, despite several requests.)

Whatever the case, the optics of the situation were terrible. Tony Stark doesn't fire Pepper Potts. He adores her and takes care of her for life. She's the only person he can really trust -- the one who has been there through everything. That Musk was willing to let Brown go and in such an unceremonious fashion struck people inside SpaceX and Tesla as scandalous and as the ultimate confirmation of his cruel stoicism. The tale of Brown's departure became part of the lore around Musk's lack of empathy. It got bundled up into the stories of Musk dressing employees down in legendary fashion with vicious barb after vicious barb. People also linked this type of behavior to Musk's other quirky traits. He's been known to obsess over typos in e-mails to the point that he could not see past the errors and read the actual content of the messages. Even in social settings, Musk might get up from the dinner table without a word of explanation to head outside and look at the stars, simply because he's not willing to suffer fools or small talk. After adding up this behavior, dozens of people expressed to me their conclusion that Musk sits somewhere on the autism spectrum and that he has trouble considering other people's emotions and caring about their well-being.

Musk's behavior matches up much more closely with someone who is described by neuropsychologists as profoundly gifted. These are people who in childhood exhibit exceptional intellectual depth and max out IQ tests. It's not uncommon for these children to look out into the world and find flaws -- glitches in the system -- and construct logical paths in their minds to fix them. For Musk, the call to ensure that mankind is a multiplanetary species partly stems from a life richly influenced by science fiction and technology. Equally it's a moral imperative that dates back to his childhood. In some form, this has forever been his mandate.

There's a tendency, especially in Silicon Valley, to label people who are a bit different or quirky as autistic or afflicted with Asperger's syndrome. It's armchair psychology for conditions that can be inherently funky to diagnose or even codify. To slap this label on Musk feels ill-informed and too easy.

Musk acts differently with his closest friends and family than he does with employees, even those who have worked alongside him for a long time. Among his inner circle, Musk is warm, funny, and deeply emotional. He might not engage in the standard chitchat, asking a friend how his kids are doing, but he would do everything in his considerable power to help that friend if his child were sick or in trouble. He will protect those close to him at all costs and, when deemed necessary, seek to destroy those who have wronged him or his friends.

Each facet of Musk's life might be an attempt to soothe a type of existential depression that seems to gnaw at his every fiber. He sees man as self-limiting and in peril and wants to fix the situation. The people who suggest bad ideas during meetings or make mistakes at work are getting in the way of all of this and slowing Musk down. He does not dislike them as people. It's more that he feels pained by their mistakes, which have consigned man to peril that much longer. The perceived lack of emotion is a symptom of Musk sometimes feeling like he's the only one who really grasps the urgency of his mission. He's less sensitive and less tolerant than other people because the stakes are so high. Employees need to help solve the problems to the absolute best of their ability or they need to get out of the way.

Musk has been pretty up front about these tendencies. He's implored people to understand that he's not chasing momentary opportunities in the business world. He's trying to solve problems that have been consuming him for decades. During our conversations, Musk went back to this very point over and over again, making sure to emphasize just how long he'd thought about electric cars and space. The same patterns are visible in his actions as well. When Musk announced in 2014 that Tesla would open-source all of its patents, analysts tried to decide whether this was a publicity stunt or if it hid an ulterior motive or a catch. But the decision was a straightforward one for Musk. He wants people to make and buy electric cars. Man's future, as he sees it, depends on this. If open-sourcing Tesla's patents means other companies can build electric cars more easily, then that is good for mankind, and the ideas should be free. The cynic will scoff at this, and understandably so. Musk, however, has been programmed to behave this way and tends to be sincere when explaining his thinking -- almost to a fault.

People in the technology industry have tended to liken Musk's drive and the scope of his ambition to that of Bill Gates and Steve Jobs. "Elon has that deep appreciation for technology, the no-holds-barred attitude of a visionary, and that determination to go after long-term things that they both had," said Edward Jung, a child prodigy who worked for Jobs and Gates and ended up as Microsoft's chief software architect. "And he has that consumer sensibility of Steve along with the ability to hire good people outside of his own comfort areas that's more like Bill. You almost wish that Bill and Steve had a genetically engineered love child and, who knows, maybe we should genotype Elon to see if that's what happened." Steve Jurvetson, the venture capitalist who has invested in SpaceX, Tesla, and SolarCity, worked for Jobs, and knows Gates well, also described Musk as an upgraded mix of the two. "Like Jobs, Elon does not tolerate C or D players," said Jurvetson. "But I'd say he's nicer than Jobs and a bit more refined than Bill Gates."

The people who get closest to Musk are the ones who learn to relate to this mode of thinking. They're the ones who can identify with his vision yet challenge him intellectually to complete it. When he asked me during one of our dinners if I thought he was insane, it was a test of sorts. We had talked enough that he knew I was interested in what he was doing. He had started to trust me and open up but wanted to make sure -- one final time -- that I truly grasped the importance of his quest. Many of his closest friends have passed much grander, more demanding tests. They've invested in his companies. They've defended him against critics. They helped him keep the wolves at bay during 2008. They've proven their loyalty and their commitment to his cause.

But the more you know about Musk, the harder it becomes to place him among his peers. Jobs is another CEO who ran two, large industry-changing companies -- Apple and Pixar. But that's where the practical similarities between the two men end. Jobs dedicated far more of his energy to Apple than Pixar, unlike Musk, who has poured equal energy into both companies, while saving whatever was left over for SolarCity. Jobs was also legendary for his attention to detail. No one, however, would suggest that his reach extended down as far as Musk's into overseeing so much of the companies' day-to-day operations. Musk's approach has its limitations. He's less artful with marketing and media strategy. Musk does not rehearse his presentations or polish speeches. He wings most of the announcements from Tesla and SpaceX. He'll also fire off some major bit of news on a Friday afternoon when it's likely to get lost as reporters head home for the weekend, simply because that's when he finished writing the press release or wanted to move on to something else. Jobs, by contrast, treated every presentation and media moment as precious. Musk simply does not have the luxury to work that way. "I don't have days to practice," he said. "I've got to give impromptu talks, and the results may vary."

The economist Tyler Cowen -- who has earned some measure of fame in recent years for his insightful writings about the state of the technology industry and his ideas on where it may go -- falls into that first camp. In The Great Stagnation, Cowen bemoaned the lack of big technological advances and argued that the American economy has slowed and wages have been depressed as a result. "In a figurative sense, the American economy has enjoyed lots of low-hanging fruit since at least the seventeenth century, whether it be free land, lots of immigrant labor, or powerful new technologies," he wrote. "Yet during the last forty years, that low-hanging fruit started disappearing, and we started pretending it was still there. We have failed to recognize that we are at a technological plateau and the trees are more bare than we would like to think. That's it. That is what has gone wrong."

As for whether Musk is leading the technology industry to new heights like Gates and Jobs, the professional pundits remain mixed. One camp holds that SolarCity, Tesla, and SpaceX offer little in the way of real hope for an industry that could use some blockbuster innovations. For the other camp, Musk is the real deal and the brightest shining star of what they see as a coming revolution in technology.

In his next book, Average Is Over, Cowen predicted an unromantic future in which a great divide had occurred between the Haves and the Have Nots. In Cowen's future, huge gains in artificial intelligence will lead to the elimination of many of today's high-employment lines of work. The people who thrive in this environment will be very bright and able to complement the machines and team effectively with them. As for the unemployed masses? Well, many of them will eventually find jobs going to work for the Haves, who will employ teams of nannies, housekeepers, and gardeners. If anything Musk is doing might alter the course of mankind toward a rosier future, Cowen can't find it. Coming up with true breakthrough ideas is much harder today than in the past, according to Cowen, because we've already mined the bulk of the big discoveries. During a lunch in Virginia, Cowen described Musk not as a genius inventor but as an attention seeker, and not a terribly good one at that. "I don't think a lot of people care about getting to Mars," he said. "And it seems like a very expensive way to drive whatever breakthroughs you might get from it. Then, you hear about the Hyperloop. I don't think he has any intention of doing it. You have to wonder if it's not meant just to be publicity for his companies. As for Tesla, it might work. But you're still just pushing the problems back somewhere else. You still have to generate power. It could be that he is challenging convention less than people think."

These sentiments are not far off from those of Vaclav Smil, a professor emeritus at the University of Manitoba. Bill Gates has hailed Smil as an important writer for his tomes on energy, the environment, and manufacturing. One of Smil's latest works is Made in the USA, an exploration of America's past manufacturing glories and its subsequent, dismal loss of industry. Anyone who thinks the United States is making a natural, clever shift away from manufacturing and toward higher-paying information-worker jobs will want to read this book and have a gander at the long-term consequences of this change. Smil presents numerous examples of the ways in which the manufacturing industry generates major innovations and creates a massive ecosystem of jobs and technical smarts around them. "For example, when some three decades ago the United States stopped making virtually all 'commodity' consumer electronic devices and displays, it also lost its capacity to develop and mass-produce advanced flat screens and batteries, two classes of products that are quintessential for portable computers and cell phones and whose large-scale imports keep adding to the US trade deficit," Smil wrote. A bit later in the book, Smil emphasized that the aerospace industry, in particular, has been a huge boon to the U. S. economy and one of its major exporters. "Maintaining the sector's competitiveness must be a key component of efforts to boost US exports, and the exports will have to be a large part of the sector's sales because the world's largest aerospace market of the next two decades will be in Asia, above all in China and India, and American aircraft and aeroengine makers should benefit from this expansion."

The comments were blunt and surprising given some of the things Smil celebrated in his recent book. He spent a good deal of time showing the positive impact that Henry Ford's vertical integration had on advancing the car industry and the American economy. He also wrote at length about the rise of "mechatronic machines," or machines that rely on a lot of electronics and software. "By 2010 the electronic controls for a typical sedan required more lines of software code than the instructions needed to operate the latest Boeing jetliner," Smil wrote. "American manufacturing has turned modern cars into remarkable mechatronic machines. The first decade of the twenty-first century also brought innovations ranging from the deployment of new materials (carbon composites in aviation, nanostructures) to wireless electronics."

Smil is consumed by the United States' waning ability to compete with China and yet does not perceive Musk or his companies as any sort of counter to this slide. "As, among other things, a historian of technical advances I simply must see Tesla as nothing but an utterly derivative overhyped toy for showoffs," Smil wrote to me. "The last thing a country with 50 million people on food stamps and 85 billion dollars deeper into debt every month needs is anything to do with space, especially space with more joyrides for the super rich. And the loop proposal was nothing but bamboozling people who do not know anything about kindergarten physics with a very old, long publicized Gedankenexperiment in kinetics… There are many inventive Americans, but in that lineup Musk would be trailing far behind."

There's a tendency among critics to dismiss Musk as a frivolous dreamer that stems first and foremost from a misunderstanding of what Musk is actually doing. People like Smil seem to catch an article or television show that hits on Musk's quest to get to Mars and immediately lump him with the space tourism crowd. Musk, though, hardly ever talks about tourism and has, since day one, built up SpaceX to compete at the industrial end of the space business. If Smil thinks Boeing selling planes is crucial to the American economy, then he should be enthused about what SpaceX has managed to accomplish in the commercial launch market. SpaceX builds its products in the United States, has made dramatic advances in aerospace technology, and has made similar advances in materials and manufacturing techniques. It would not take much to argue that SpaceX is America's only hope of competing against China in the next couple of decades. As for mechatronic machines, SpaceX and Tesla have set the example of fusing together electronics, software, and metal that their rivals are now struggling to match. And all of Musk's companies, including SolarCity, have made dramatic use of vertical integration and turned in-house control of components into a real advantage.

To get a sense of how powerful Musk's work may end up being for the American economy, have a think about the dominant mechatronic machine of the past several years: the smartphone. Pre-iPhone, the United States was the laggard in the telecommunications industry. All of the exciting cell phones and mobile services were in Europe and Asia, while American consumers bumbled along with dated equipment. When the iPhone arrived in 2007, it changed everything. Apple's device mimicked many of the functions of a computer and then added new abilities with its apps, sensors, and location awareness. Google charged to market with its Android software and related handsets, and the United States suddenly emerged as the driving force in the mobile industry. Smartphones were revolutionary because of the ways they allowed hardware, software, and services to work in unison. This was a mix that favored the skills of Silicon Valley. The rise of the smartphone led to a massive industrial boom in which Apple became the most valuable company in the country, and billions of its clever devices were spread all over the world.

Tony Fadell, the former Apple executive credited with bringing the iPod and iPhone to market, has characterized the smartphone as representative of a type of super-cycle in which hardware and software have reached a critical point of maturity. Electronics are good and cheap, while software is more reliable and sophisticated. Their interplay is now resulting in science fiction-worthy ideas we were promised long ago becoming a reality. Google has its self-driving cars and has acquired dozens of robotics companies as it looks to merge code and machine. Fadell's company Nest has its intelligent thermostats and smoke alarms. General Electric has jet engines packed full of sensors taught to proactively report possible anomalies to its human mechanics. And a host of start-ups have begun infusing medical devices with powerful software to help people monitor and analyze their bodies and diagnose conditions. Tiny satellites are being put into orbit twenty at a time, and instead of being given a fixed task for their entire lifetimes, like their predecessors, they're being reprogrammed on the fly for a wide variety of business and scientific tasks. Zee Aero, a start-up in Mountain View, has a couple of former SpaceX staffers on hand and is working on a secretive new type of transport. A flying car at last? Perhaps.

To the extent that Silicon Valley has searched for an inheritor to Steve Jobs's role as the dominant, guiding force of the technology industry, Musk has emerged as the most likely candidate. He's certainly the "it" guy of the moment. Start-up founders, proven executives, and legends hold him up as the person they most admire. The more mainstream Tesla can become, the more Musk's reputation will rise. A hot-selling Model 3 would certify Musk as that rare being able to rethink an industry, read consumers, and execute. From there, his more fanciful ideas start to seem inevitable. "Elon is one of the few people that I feel is more accomplished than I am," said Craig Venter, the man who decoded the human genome and went on to create synthetic lifeforms. At some point he hopes to work with Musk on a type of DNA printer that could be sent to Mars. It would, in theory, allow humans to create medicines, food, and helpful microbes for early settlers of the planet. "I think biological teleportation is what is going to truly enable the colonization of space," he said. "Elon and I have been talking about how this might play out."

For Fadell, Musk's work sits at the highest end of this trend. "He could have just made an electric car," Fadell said. "But he did things like use motors to actuate the door handles. He's bringing the consumer electronics and the software together, and the other car companies are trying to figure out a way to get there. Whether it's Tesla or SpaceX taking Ethernet cables and running them inside of rocket ships, you are talking about combining the old-world science of manufacturing with low-cost, consumer-grade technology. You put these things together, and they morph into something we have never seen before. All of a sudden there is a wholesale change," he said. "It's a step function."

Google has invested more than just about any other technology company into Musk's sort of moon-shot projects: self-driving cars, robots, and even a cash prize to get a machine onto the moon cheaply. The company, however, operates under a set of constraints and expectations that come with employing tens of thousands of people and being analyzed constantly by investors. It's with this in mind that Page sometimes feels a bit envious of Musk, who has managed to make radical ideas the basis of his companies. "If you think about Silicon Valley or corporate leaders in general, they're not usually lacking in money," Page said. "If you have all this money, which presumably you're going to give away and couldn't even spend it all if you wanted to, why then are you devoting your time to a company that's not really doing anything good? That's why I find Elon to be an inspiring example. He said, 'Well, what should I really do in this world? Solve cars, global warming, and make humans multiplanetary.' I mean those are pretty compelling goals, and now he has businesses to do that."

One of Musk's most ardent admirers is also one of his best friends: Larry Page, the cofounder and CEO of Google. Page has ended up on Musk's house-surfing schedule. "He's kind of homeless, which I think is sort of funny," Page said. "He'll e-mail and say, 'I don't know where to stay tonight. Can I come over?' I haven't given him a key or anything yet."

"This becomes a competitive advantage for him, too. Why would you want to work for a defense contractor when you can work for a guy who wants to go to Mars and he's going to move heaven and earth to make it happen? You can frame a problem in a way that's really good for the business."

At one point, a quotation from Page made the rounds, saying that he wanted to leave all of his money to Musk. Page felt he was misquoted but stood by the sentiment. "I'm not leaving my money to him at the moment," Page said. "But Elon makes a pretty compelling case for having a multiplanetary society just because, you know, otherwise we might all die, which seems like it would be sad for all sorts of different reasons. I think it's a very doable project, and it's a relatively modest resource that we need to set up a permanent human settlement on Mars. I was just trying to make the point that that's a really powerful idea."

As Page puts it, "Good ideas are always crazy until they're not." It's a principle he's tried to apply at Google. When Page and Sergey Brin began wondering aloud about developing ways to search the text inside of books, all of the experts they consulted said it would be impossible to digitize every book. The Google cofounders decided to run the numbers and see if it was actually physically possible to scan the books in a reasonable amount of time. They concluded it was, and Google has since scanned millions of books. "I've learned that your intuition about things you don't know that much about isn't very good," Page said. "The way Elon talks about this is that you always need to start with the first principles of a problem. What are the physics of it? How much time will it take? How much will it cost? How much cheaper can I make it? There's this level of engineering and physics that you need to make judgments about what's possible and interesting. Elon is unusual in that he knows that, and he also knows business and organization and leadership and governmental issues."

Some of the conversations between Musk and Page take place at a secret apartment Google owns in downtown Palo Alto. It's inside of one of the taller buildings in the area and offers views of the mountains surrounding the Stanford University campus. Page and Brin will take private meetings at the apartment and have their own chef on call to prepare food for guests. When Musk is present, the chats tend toward the absurd and fantastic. "I was there once, and Elon was talking about building an electric jet plane that can take off and land vertically," said George Zachary, the venture capitalist and friend of Musk's. "Larry said the plane should be able to land on ski slopes, and Sergey said it needed to be able to dock at a port in Manhattan. Then they started talking about building a commuter plane that was always circling the Earth, and you'd hop up to it and get places incredibly fast. I thought everyone was kidding, but at the end I asked Elon, 'Are you really going to do that?' And he said, 'Yes.'"

"It's kind of our recreation, I guess," said Page. "It's fun for the three of us to talk about kind of crazy things, and we find stuff that eventually turns out to be real. We go through hundreds or thousands of possible things before arriving at the ones that are most promising."

Page holds Musk up as a model he wishes others would emulate -- a figure that should be replicated during a time in which the businessmen and politicians have fixated on short-term, inconsequential goals. "I don't think we're doing a good job as a society deciding what things are really important to do," Page said. "I think like we're just not educating people in this kind of general way. You should have a pretty broad engineering and scientific background. You should have some leadership training and a bit of MBA training or knowledge of how to run things, organize stuff, and raise money. I don't think most people are doing that, and it's a big problem. Engineers are usually trained in a very fixed area. When you're able to think about all of these disciplines together, you kind of think differently and can dream of much crazier things and how they might work. I think that's really an important thing for the world. That's how we make progress."

Page talked about Musk at times as if he were a one-of-a-kind, a force of nature able to accomplish things in the business world that others would never even try. "We think of SpaceX and Tesla as being these tremendously risky things, but I think Elon was going to make them work no matter what. He's willing to suffer some personal cost, and I think that makes his odds actually pretty good. If you knew him personally, you would look back to when he started the companies and say his odds of success would be more than ninety percent. I mean we just have a single proof point now that you can be really passionate about something that other people think is crazy and you can really succeed. And you look at it with Elon and you say, 'Well, maybe it's not luck. He's done it twice. It can't be luck totally.' I think that means it should be repeatable in some sense. At least it's repeatable by him. Maybe we should get him to do more things."

Suffering, though, has always been Musk's thing. The kids at school tortured him. His father played brutal mind games. Musk then abused himself by working inhumane hours and forever pushing his businesses to the edge. The idea of work-life balance seems meaningless in this context. For Musk, it's just life, and his wife and kids try to fit into the show where they can. "I'm a pretty good dad," Musk said. "I have the kids for slightly more than half the week and spend a fair bit of time with them. I also take them with me when I go out of town. Recently, we went to the Monaco Grand Prix and were hanging out with the prince and princess of Monaco. It all seemed quite normal to the kids, and they were blasé about it. They are growing up having a set of experiences that are extremely unusual, but you don't realize experiences are unusual until you are much older. They're just your experiences. They have good manners at meals."

The pressure of feeling the need to fix the world takes its toll on Musk's body. There are times when you run into Musk and he looks utterly exhausted. He does not have bags under his eyes but rather deep, shadowy valleys. During the worst of times, following weeks of sleep deprivation, his eyes seem to have sunk back into his skull. Musk's weight moves up and down with the stress, and he's usually heavier when really overworked. It's funny in a way that Musk spends so much time talking about man's survival but isn't willing to address the consequences of what his lifestyle does to his body. "Elon came to the conclusion early in his career that life is short," Straubel said. "If you really embrace this, it leaves you with the obvious conclusion that you should be working as hard as you can."

It bothers Musk a bit that his kids won't suffer like he did. He feels that the suffering helped to make him who he is and gave him extra reserves of strength and will. "They might have a little adversity at school, but these days schools are so protective," he said. "If you call someone a name, you get sent home. When I was going to school, if they punched you and there was no blood, it was like, 'Whatever. Shake it off.' Even if there was a little blood, but not a lot, it was fine. What do I do? Create artificial adversity? How do you do that? The biggest battle I have is restricting their video game time because they want to play all the time. The rule is they have to read more than they play video games. They also can't play completely stupid video games. There's one game they downloaded recently called Cookies or something. You literally tap a fucking cookie. It's like a Psych 101 experiment. I made them delete the cookie game. They had to play Flappy Golf instead, which is like Flappy Bird, but at least there is some physics involved."

Musk has talked about having more kids, and it's on this subject that he delivers some controversial philosophizing vis-à-vis the creator of Beavis and Butt-head. "There's this point that Mike Judge makes in Idiocracy, which is like smart people, you know, should at least sustain their numbers," Musk said. "Like, if it's a negative Darwinian vector, then obviously that's not a good thing. It should be at least neutral. But if each successive generation of smart people has fewer kids, that's probably bad, too. I mean, Europe, Japan, Russia, China are all headed for demographic implosion. And the fact of the matter is that basically the wealthier -- basically wealth, education, and being secular are all indicative of low birth rate. They all correlate with low birth rate. I'm not saying like only smart people should have kids. I'm just saying that smart people should have kids as well. They should at least maintain -- at least be a replacement rate. And the fact of the matter is that I notice that a lot of really smart women have zero or one kid. You're like, 'Wow, that's probably not good.'"

The next decade of Musk Co. should be quite something. Musk has given himself a chance to become one of the greatest businessmen and innovators of all time. By 2025 Tesla could very well have a lineup of five or six cars and be the dominant force in a booming electric car market. Playing off its current growth rate, SolarCity will have had time to emerge as a massive utility company and the leader in a solar market that had finally lived up to its promise. SpaceX? Well, it's perhaps the most intriguing. According to Musk's calculations, SpaceX should be conducting weekly flights to space, carrying humans and cargo, and have put most of its competitors out of business. Its rockets should be capable of doing a couple of laps around the moon and then landing with pinpoint accuracy back at the spaceport in Texas. And the preparation for the first few dozen trips to Mars should be well under way.

If all of this were taking place, Musk, then in his mid-fifties, likely would be the richest man in the world and among its most powerful. He would be the majority shareholder in three public companies, and history would be preparing to smile broadly on what he had accomplished. During a time in which countries and other businesses were paralyzed by indecision and inaction, Musk would have mounted the most viable charge against global warming, while also providing people with an escape plan -- just in case. He would have brought a substantial amount of crucial manufacturing back to the United States while also providing an example for other entrepreneurs hoping to harness a new age of wonderful machines. As Thiel said, Musk may well have gone so far as to give people hope and to have renewed their faith in what technology can do for mankind.

This future, of course, remains precarious. Huge technological issues confront all three of Musk's companies. He's bet on the inventiveness of man and the ability of solar, battery, and aerospace technology to follow predicted price and performance curves. Even if these bets hit as he hopes, Tesla could face a weird, unexpected recall. SpaceX could have a rocket carrying humans blow up -- an incident that could very well end the company on the spot. Dramatic risks accompany just about everything Musk does.

By the time our last dinner had come around, I had decided that this propensity for risk had little to do with Musk being insane, as he had wondered aloud several months earlier. No, Musk just seems to possess a level of conviction that is so intense and exceptional as to be off-putting to some. As we shared some chips and guacamole and cocktails, I asked Musk directly just how much he was willing to put on the line. His response? Everything that other people hold dear. "I would like to die on Mars," he said. "Just not on impact. Ideally I'd like to go for a visit, come back for a while, and then go there when I'm like seventy or something and then just stay there. If things turn out well, that would be the case. If my wife and I have a bunch of kids, she would probably stay with them on Earth."