TIME graphic by Lon Tweeten The date of the first crewed launch of Starship has not been firmly set, but it will be an Earth-orbital mission commanded by billionaire and veteran space traveler Jared Isaacman. (Isaacman commanded the Inspiration4 mission, aboard a SpaceX Crew Dragon spacecraft, in 2021.) Yusaka Maezawa, a Japanese fashion magnate, has also bought nine seats aboard a Starship rocket for his dearMoon mission, a circumlunar journey that was originally planned for the end of this year and now will take place sometime after Isaacman’s flight. Much more important, though, is Starship’s role in NASA’s Artemis program. In April 2021, NASA selected the Starship upper stage as the vehicle that will serve as the program’s Human Landing System (HLS)—the 21st century version of the Apollo era’s lunar module. The company was awarded an exclusive contract to build the HLS, beating out two competitors for the coveted deal: Houston-based Dynetics and Amazon founder Jeff Bezos’s Kent, Washington-based Blue Origin. The decision raised some eyebrows. The other two companies publicly griped that NASA should have selected at least two providers to build the HLS, as it did in 2014 when it awarded contracts to both Boeing and SpaceX to build vehicles to fly crew to the International Space Station (ISS). Other space watchers questioned the choice too. Dynetics’ and Blue Origin’s proposed landers are low-slung, four-legged machines like the old lunar module, with an equally low center of gravity, increasing the stability of the machine if it lands on uneven lunar terrain. The silo-like, 164-ft. Starship is a different matter, potentially prone to tipping if its own four legs don’t set down on a flat surface. “When you look at that huge thing on an unprepared terrain like it will be on the surface of the moon, it’s a little bit scary,” says Pablo de Leon, the chair of the department of space studies at the University of North Dakota. “You don’t have that low center of gravity.” But NASA has faith in SpaceX—and not without justification: the company has made seven crewed flights to the ISS aboard its Crew Dragon spacecraft since 2020, and 27 uncrewed cargo runs to the station since 2012. What’s more, SpaceX has consistently served the private and public sectors, with 216 launches of its workhorse Falcon 9 rocket since 2010, including 61 in 2022 alone. “NASA has been able to get a lot of bang for its buck using SpaceX as a commercial provider,” says de Leon. “We’re seeing up to a couple of launches per week from SpaceX. That’s not a small accomplishment.” “These guys are the real deal,” adds Scott Pace, a professor at George Washington University’s Space Policy Institute. But not everyone is as positive about Starship in particular and SpaceX in general. A 33-engine machine is, as de Leon puts it, “a nightmare for the plumbers,” one that calls to mind the old Soviet Union’s 30-engine N-1 moon rocket, which never successfully flew and, in one test in 1969, blew up just after liftoff, causing the largest explosion in space history. What’s more, 16.7 million pounds of thrust, while impressive, is far more than is needed to carry a payload to low-Earth orbit (LEO)—which is the destination of the vast majority of space launches. “It’s like using a sledgehammer to crack a nut,” says Sa’id Mosteshar, director of the London Institute of Space Policy and Law. “We certainly don’t need anything that powerful.” Musk does not disagree and has long said that Starship would be used not for LEO taxi runs, but principally for missions that require much greater propulsive power: both to the moon and Mars—with Martian colonization in his long-term sights, given that the upper Starship stage could be configured to carry up to 100 passengers. Others worry that Musk has taken advantage of NASA’s repeated and generous contracts to make himself too central to the space agency’s operations—a single provider serving as principal carrier of crew and cargo to the ISS as well as crew to the moon. “It certainly is” a problem, says Mosteshar, with the space agency facing the risk of being effectively paralyzed if technical problems or a launch disaster caused SpaceX to go offline even for a while, the way the U.S. was grounded after both the Challenger and Columbia shuttle disasters. “It increases the risk, having just one entity,” Mosteshar adds. “I don’t have a big concern about whether Starship will succeed or not,” says Pace. “My question is, does the business plan work?” That concern is a greater one for NASA than for SpaceX. Musk, clearly, has worked out his business plan—bestriding both the private and public sectors—with his biggest launch of his biggest rocket yet to come. Whether Starship and SpaceX themselves are too big is a question that has yet to be answered. Starship Rising Starship’s development has not always been a pretty thing to watch. From 2020 to 2021, five upper stage Starship rockets were launched on short test flights—to a maximum altitude of 10 km (6.2 mi.)—four of which ended in explosions or crashes before a fifth finally succeeded, and even that one included a small fire at the base of the rocket after landing. But flying fast, failing fast, and trying again have always been part of the SpaceX R&D model. “It’s like a spiral design, where they build, test, fly, learn from that and then cycle through again,” says Lisa Watson-Morgan, NASA’s program manager for the Artemis Human Landing System. “And so what we see is a lot of activity and a lot of testing right now.” Starship 25 stands on a suborbital pad at SpaceX's south Texas facility near Brownsville, Texas, on Jan. 24, 2023. Reginald Mathalone—NurPhoto/Reuters Lately, that testing has included multiple static firings of the Starship engines—with the rocket anchored to the pad so it goes nowhere while the engines burn. The engines, a new design dubbed Raptor, burn liquid methane and liquid oxygen, rather than the mix of a kerosene-like fuel and liquid oxygen used by SpaceX’s Falcon rockets, giving Starship higher performance and allowing the weight of the engine—and the overall rocket—to be reduced. And while methane is a powerful greenhouse gas, it burns cleaner than kerosene and more efficiently than the liquid oxygen and hydrogen that powered the second stage of the Saturn V. Most recently, on Feb. 9, the company static-fired 31 of the 33 main stage engines, proving the mettle of the overall system. “Team turned off 1 engine just before start & 1 stopped itself, so 31 engines fired overall. But still enough engines to reach orbit!” Musk said via Twitter at the time. Once Starship does launch, Musk envisions moving ahead at head-snapping speed. His goal, as he tweeted last June, is to “Build 1000+ Starships to transport life to Mars. Basically, (very) modern Noah’s Arks.” Other interested parties are less hyperbolic, but no less optimistic. “As soon as that thing launches the first time, they’re going to learn so much and they’re going to be at warp speed,” says Isaacman. “I have no doubt there will be a lot of hardware and engines just ready to go.” To the Moon Despite Musk’s private sector customers and his long-term dreams of Mars colonization, it is Starship’s role in the Artemis lunar program that is its showpiece function—and there is a lot of planning ahead before the ship will be ready to make that trip. Landing on the moon with Starship will be nowhere near as straightforward as it was in the Apollo days. Back then, a single Saturn V rocket launched both the lunar lander and the orbiting mothership in one go, and both spacecraft flew out to the moon linked together. The Artemis program will be a multi-step affair involving two rockets—the SLS and the Starship—operating in tandem. Starship will launch first. Once its upper stage gets part way to Earth orbit, the Superheavy booster will separate and land back on Earth. The upper stage will then use its own array of six engines to power its way into orbit. Doing this will exhaust most of its fuel supply—but its gas tank won’t remain empty for long. Ready and waiting for it will be a fuel depot—launched into orbit by SpaceX—where Starship will rendezvous to refill itself sufficiently to power its way out of Earth orbit, to the moon, and then down to the lunar surface and back up. The only thing missing, of course, are the astronauts. Once Starship has entered lunar orbit it will, as Watson-Morgan puts it, “loiter” there. A crew of four astronauts will then ride the Orion spacecraft, launched atop the SLS, out to the moon and dock with the waiting Starship. Two of the crew members will then transfer to Starship and descend to the surface. Watson-Morgan is sanguine about the Starship’s ability to stick the lunar landing despite any ruggedness of the terrain, because of a feature SpaceX is designing into the spacecraft’s four landing legs. “Each leg has active and independent control authority,” she says. “So if one lands higher up on a rock or a ledge or something, it can level itself with the others.” Assuming that system works and all goes well, the two lunar explorers will spend just under a week on the surface before lifting back off and re-docking with the Orion. All four astronauts will then fly home aboard the Orion, while the Starship remains in the lunar vicinity as a very pricey piece of space junk. Other Partners All of these moving parts are being developed in the service of a larger vision for lunar exploration. NASA intends to eventually launch a mini-lunar space station known as Gateway to act as a sort of way station for the future Orions and Starships. A central travel hub like that will serve the multiple landings NASA envisions for Artemis 4, 5, 6, and beyond. The first Gateway module will be launched aboard yet another SpaceX rocket—the 27-engine Falcon Heavy—as early as November of 2024. Once Gateway is in operation, NASA intends to move away from exclusive reliance on Starship for its human landing system. The space agency is now opening the door for other bidders to build a second lander to provide services along with Starship—with Blue Origin and Dynetics the two contenders. In a statement at the time of the announcement in March 2022, Watson-Morgan said this would help the Artemis program advance as flights to the moon become more frequent and complex, providing flexibility and redundancy. Adds Pace, straightforwardly: “If one goes down, I’ve got another.” Multiple landers will also help with NASA’s ultimate goal: establishing a permanent base on the lunar surface. It is that kind of multiplicity of options that gives other space experts, unlike Mosteshar, confidence that NASA has not allowed Musk and SpaceX to become too central to its operations. “We’ve never had so many missions as we have today,” says astrophysicist Pascal Ehrenfreund, a professor at the George Washington University Space Policy Institute. “That’s because there’s cooperation between NASA and SpaceX and other companies and entrepreneurs. It makes the entire exploration era versatile and dynamic.” De Leon agrees that the faster other companies come online and get their hardware flying, the better off NASA will be. “It’s smart for NASA to keep its options open,” he says. “You don’t want to put your eggs in one basket.” Of course, the basket that is Starship has itself yet to fly, and until it does, NASA’s Artemis plans and Musk’s Mars dreams are all just that—plans and dreams. De Leon, while not predicting if the first flight will be a success, does believe Starship has the engineering cred to work as planned. “Elon Musk has shown that he is a careful designer and his team is certainly capable,” he says. “I don’t think they would be doing this design if they didn’t go through the necessary process to prove that it is feasible now.” “Every Mars [mission] plan you’ve ever looked at says that you need to build the biggest rocket you possibly can,” says Pace. Musk has done just that. Before long, the giant machine will prove if it is up to the jobs that have been assigned to it. More Must-Reads from TIME