SpaceX Stands Behind Its Ambitious Lunar Timeline

SpaceX’s Starship, sometimes referred to by the company simply as “Ship,” is the largest and most powerful rocket to ever fly. When stacked atop the firm’s Super Heavy booster, it stands nearly 400 feet tall—nearly as high as the Great Pyramid of Giza. Super Heavy’s 33 Raptor engines generate close to 17 million pounds of thrust at liftoff, nearly double NASA’s Space Launch System (SLS).

A human landing system (HLS) variant of Starship will be the vehicle to land NASA astronauts on the moon during Artemis III and handle many of the mission’s historic feats. So far, the spacecraft has completed a handful of test missions in Earth orbit, some of which ended the same way they began—in a ball of flames. But this year will be SpaceX’s chance to prove Ship can make it to the moon and, perhaps, beyond.

Though Artemis III will mark Americans’ first trip to the moon since the Apollo era, the mission will look a little different than its predecessors.

The SLS will launch a four-person crew to orbit from Launch Pad 39B at Kennedy Space Center in Florida, in NASA’s Orion capsule. Orion will spend a few days circling the Earth before launching to what is known as near-rectilinear halo orbit (NRHO)—a fancy term for an orbit shaped by both the Earth and moon’s gravity.

Unlike Apollo—which used a single spacecraft comprising a mothership and lunar lander—Artemis III will see Orion dock with Starship HLS in NRHO. Two crewmembers will then descend to the moon’s south pole for a weeklong expedition, with the HLS serving as a shelter, workspace, and base of communications with mission control in Houston.

Once the astronauts’ work is complete, Starship will return them to Orion, which will slingshot them around the moon and back toward Earth. 

Before that, though, SpaceX has work to do. The company must launch a fuel storage depot to Earth orbit, which will give Starship HLS the juice it needs to fly to the moon (the fuel it receives on Earth will only be enough to escape the planet’s gravity). A tanker variant of Ship will stock up the depot.

Artemis III is more complex than the Apollo missions not only due to the number of spacecraft required, but the number of flights. NASA, for example, in 2023 estimated the mission will call for about 15 tanker trips to fuel up the orbital depot. SpaceX CEO Elon Musk believes the company can cut that figure in half. Either way, to get there, Ship needs to hit several crucial milestones in 2025.

Given its unmatched size and power, Starship was unlikely to achieve all of SpaceX’s goals on the first go. But SpaceX never expected it to. Per the company’s mantra of iterative design, each test flight—whether it goes according to plan or not—is invaluable.

Ship’s first two flights fell in the latter bucket, exploding before they reached orbit. But the company rebounded from its mistakes, flying halfway around the planet on the following mission. During Flight 4, the massive rocket made it back to Earth. By the fifth test flight, SpaceX managed something unprecedented—snaring the Super Heavy booster in midair using a pair of metal “chopstick” arms.

That last achievement bodes well for Ship’s next 365 days. SpaceX hopes to cut mission turnaround time from months to days—or even hours—by making both Starship and Super Heavy fully reusable. Flight 5 proved it was possible to return the booster to the same pad from which it launched. Flight 6 brought the company closer to achieving the same for Ship itself.

“We will do one more ocean landing of the ship,” Musk said in a post on X after that mission. “If that goes well, then SpaceX will attempt to catch the ship with the tower.”

In November, Kathy Lueders, general manager of SpaceX’s Starbase launch pad in south Texas, said the company aims to launch Starship 25 times this year, or about once every two weeks. Little is known about the next mission, Flight 7, except that it will introduce the next iteration of Ship. The new model is designed to fly payloads up to 100 tons to orbit and will carry 25 percent more propellant. According to SpaceX, it will feature redesigned flaps and heat shield tiles.

Per comments from Musk and those in his orbit, the following test could feature the first attempt to catch Starship’s upper stage. Lueders in November set a goal to catch Ship by May. Alternatively, that mission could be a propellant transfer demonstration—arguably the most important and miraculous feat Ship has yet to achieve. The transfer of supercooled fuel between two orbiting vehicles, such as the cryogenically cooled liquid oxygen and methane used by Starship, has never been attempted. According to NASA, SpaceX as early as March will send two Ships, launched a few weeks apart, to dock autonomously in orbit and move as much as 1,500 tons of propellant.

Engineers will gauge how well the system prevents the liquid fuel from evaporating—even in the cold vacuum of space, heat, such as from solar radiation, can cause it to “boil off.” That will help NASA estimate how many Starship tankers will be needed to fuel up the orbital propellant depot.

While it may sound inconsequential, Starship’s orbital refueling capability is the key to getting the HLS to the moon—and one day, as Musk predicts, Mars.

Should SpaceX achieve the two goals above, the company’s 2025 may culminate in Starship’s first visit to the moon, as NASA and SpaceX officials predicted two years ago. The uncrewed demonstration, part of the firm’s multibillion-dollar Artemis contract, would serve as a final dress rehearsal for the real deal.

Just over 18 months ago, SpaceX went from contending with exploding rockets, FAA investigations, and environmental lawsuits, to pulling off one of the most precise maneuvers in the history of spaceflight on its first try. But the company may need to pick up the pace to meet NASA’s impending Artemis III target.

Two years ago the space agency decided to push the mission back, citing the development of Starship HLS as a factor. A November 2023 report from the U.S. Government Accountability Office (GAO), meanwhile, acknowledged SpaceX’s progress but predicted HLS delays could cause a further slip to 2027. It singled out the development of the spacecraft’s Raptor engines, in particular, as a “top risk.”

As it turns out, the GAO’s prediction was correct—NASA in December announced that Artemis III would slide until mid-2027. Amit Kshatriya, deputy associate administrator of NASA’s Moon to Mars Program, said “there are going to be risks” to SpaceX’s ability to complete the Ship propellant transfer demonstration on the space agency’s timeline.

NASA further attributed Artemis delays to issues with the Orion heat shield that flew on Artemis I back in 2022. Engineers identified a design flaw that caused the capsule to lose its outer layer of protective thermal material as it experienced temperatures approaching 15,000 degrees Fahrenheit when reentering the atmosphere. The same heat shield will fly on Artemis II but be replaced ahead of Artemis III.

NASA will need to sort out some of these issues itself. But it will also depend on SpaceX to hold up its end of the bargain—and 2025 is the firm’s make-or-break year.

This feature first appeared in the January Issue 954 of the FLYING print edition.