Silicon Valley billionaire Elon Musk’s palpable love for flame throwers may be rivaled by just one thing: his passion for outer space. Through his private aerospace company, SpaceX, Musk has said he hopes to gradually increase the caliber of craft able to land on Mars, with the eventual goal of sending human explorers, and colonizing the planet. At South by Southwest this weekend, Musk issued an update on SpaceX’s Mars progress, telling the crowd that the first Mars-bound SpaceX ship is currently in production, and he hopes it will be able to complete brief “up and down” flights during the first half of next year. “People have told me that my timelines historically have been optimistic,” he said. “And so I'm trying to recalibrate to some degree here.”

For all Musk’s talk of space travel, he finds a formidable rival in another Silicon Valley billionaire: Jeff Bezos. While Musk has the functioning infrastructure in place and is working to create a viable business with SpaceX, which he said on Sunday is “alive by the skin of its teeth,” Bezos has nearly unlimited assets to devote to his aerospace company, Blue Origin. Previously, the Amazon C.E.O. said he would fund his space exploration enterprise through the sale of Amazon stock, and on Saturday night, while accepting the Buzz Aldrin Space Exploration Award at the Explorers Club Annual Dinner, he confirmed his commitment to the project. “The price of admission to space is very high,” he said. “I’m in the process of converting my Amazon lottery winnings into a much lower price of admission so we can go explore the solar system.”

Though Bezos declined to detail just how much his “winnings” are worth, both he and Musk epitomize the trend toward private space ventures. Governments, including the Trump White House, have indicated their interest in space exploration; in the 2018 budget, the president requested more than $800 million in funding for NASA moon missions. But even that request pales in comparison to the record amounts of cash V.C.s are pouring into space travel—in 2017, overall investment in space start-ups by venture capitalists reached a record $2.8 billion. Tokyo-based start-up ispace raised more than $90 million last year, and is aiming to land rover vehicles on the moon by 2020. “What’s going to happen next is a kind of land grab,” said ispace C.E.O. Takeshi Hakamada told Bloomberg. “It’s going to be first-come, first-served.”

The various rivalries suggest that the next space race won’t be fought between countries, but between billionaires pouring money into private ventures. So far, prospects for intergalactic profit may be limited—as Carolyn Belle, an analyst at Northern Sky Research, pointed out, “there isn’t a large potential customer base.” But the mission retains its urgency for Musk, who said at SXSW over the weekend that “It’s important to get a self-sustaining base on Mars because it’s far enough away from Earth that [in the event of a war] it’s more likely to survive than a moon base. If there’s a third world war, we want to make sure there’s enough of a seed of human civilization somewhere else to bring it back and shorten the length of the dark ages,” he added. But using another planet as a backup is reportedly “unmotivating” for Bezos. “We have sent a lot of probes to every planet in this solar system. Believe me, this is the best one,” he said. “The world that we live on is an absolute gem.”