White House Moves To End NASA’s SLS, Orion and Gateway

Since Apollo, NASA’s human space programs have been defined by its vehicles: the Saturn V that sent astronauts to the Moon, the space shuttles that pioneered research and satellite servicing from low Earth orbit, and the International Space Station, where a partnership of countries continue to learn about long-term space operations and sustainability.

But those days may be numbered. The Trump administration wants to cut NASA funding by 24% and end several flagship programs, including its Space Launch System (SLS) rocket and Orion spacecraft, moves that raise questions about the agency’s future amid growing technical capabilities in the private sector.

Things began to change when NASA started flying International Space Station (ISS) crews on SpaceX rockets and capsules, which left the agency enough money—at least for a time—to work on its next flagship human space program, Artemis.

• Proposal cuts $6 billion from NASA budget
• Flagship science programs face cancellation
• SLS, Orion, Gateway could end

Like its predecessors, the Artemis initiative is built around NASA-owned and operated systems, including the heavy-lift SLS and four-person Orion, both of which are designed for deep-space travel.

Neither system is the best offering by the sharpest minds in the business. Congress directed NASA to design the SLS using 1970s-era space shuttle technology and hardware, ostensibly to facilitate an easy transition from one flagship program to the next. The agency added a fifth segment to the shuttle’s solid rocket boosters, stretched its external fuel tank height to 212 ft. from 154 ft. to accommodate 730,000 gal. of propellant, and modified the reusable Aerojet Rocketdyne RS-25 engines for onetime use on the system.

Orion was paired with a European Service Module, although the module lacks enough delta-v to put the spacecraft into a low lunar orbit to support sorties to the Moon’s surface. To bridge the gap, NASA added a small lunar-orbiting station, known as the Gateway, as a transfer hub. The agency is counting on partnership arrangements with SpaceX and Blue Origin to provide last-leg astronaut travel services to and from the Moon aboard Human Landing Systems (HLS) that NASA neither owns nor operates.

There are enough shuttle engines left for four SLS flights, but if the White House’s fiscal 2026 budget plan passes, SLS will not make it that far. A summary budget released May 2 calls for NASA to phase out the SLS and Orion after two more flights and cancel the Gateway, which includes contributions by partner countries as a follow-on to the ISS program.

“The technical foundations of Artemis are questionable,” says John Logsdon, founder and former director of George Washington University’s Space Policy Institute. “You’re dependent on a launcher, which most people say is the wrong launcher, and it is ridiculously expensive. For landing on the Moon, you’re depending on hardware that hasn’t been created yet. You have the architecture calling for the Gateway, for which a clear need hasn’t been established. I think Artemis as a technological project is on rather shaky grounds.”

NASA’s baseline plan calls for an initial 10 SLS missions under its Artemis lunar exploration initiative. “Until there is a reasonable alternative to SLS, we have to use it,” former NASA Deputy Administrator Pamela Melroy says. “That may mean it never flies more than the 10 missions that are on the books. The question is when.”

After more than a decade of development, the SLS debuted on Nov. 16, 2022, to put an uncrewed Orion spacecraft on a flight test around the Moon. Artemis II, a crewed flight test, is to follow next year. Under the Trump administration’s spending plan, the third launch of the SLS, which is intended to land astronauts on the Moon, would be its finale. Private industry would assume the job of carrying future crews into deep space—a capability that does not yet exist.

The White House’s top-line spending plan also almost halves NASA’s $7.3 billion science budget and ends a joint U.S.-European flagship mission to bring back samples from Mars, the planetary science community’s highest priority. Since 2021, NASA’s Perseverance rover has been exploring Jezero Crater, an ancient Martian basin that was once filled with water, and caching samples for a future return to Earth. The site is considered one of the best places to search for evidence of past microbial life on Mars.

Overall, the administration wants to reduce NASA’s current $24.8 billion annual budget to $18.8 billion, a level not seen in inflation-adjusted dollars since 1961, according to a database maintained by The Planetary Society, a nonprofit science advocacy organization.

The proposed spending plan leaves Republican legislators, particularly those with NASA centers in their districts, pitted between party loyalties and parochial interests. “This is a real test,” Planetary Society Space Policy Chief Casey Dreier says. “Is it better to be aligned with your president on this issue if you’re a Republican, or is it better to protect your economic interests in your state? Which one is better for your career?

“The level of political support for SLS or Orion should never be underestimated, given how stable it’s been over the years,” he adds. “My fear is that is what gets the political congressional attention, and science is left to twist in the wind.”

Rep. Brian Babin (R.-Texas), whose district includes NASA’s Johnson Space Center, noted that the Trump administration’s proposal is just the beginning of the budget process, not a final decision. “For over two decades, Congress has charted a bipartisan, sustainable path for space exploration,” he said in a statement. “I remain dedicated to staying the course, honoring our national space priorities, and supporting NASA and the many vital programs it oversees.”

Babin chairs the House Science, Space and Technology Committee, which oversees the agency.

NASA spent about $50 billion on the SLS, Orion and ground support systems between 2006 and the rocket’s debut in 2022. “The SLS is neither reusable nor cheap, costing between $876 million and $2 billion per launch, depending on how one accounts for its related overhead costs,” Dreier says.

Given the system’s high cost and growing capabilities in the private sector, the rationale for SLS comes down to politics. “Depending on how you look at it, the SLS is either a product of a broken system that curries favor to wealthy industries, or it is an example of representative democracy working as it should—with members of Congress responding to the local needs of their constituents. Perhaps it’s a bit of both,” Dreier says.

The leading contender to replace SLS is SpaceX’s Starship-Super Heavy, a fully reusable two-stage transportation system currently in development. NASA purchased a variant of Starship for its first two lunar landings, ferrying crews between the Orion spacecraft or the Gateway in lunar orbit and the surface of the Moon.

“If you had told me in 2009-10 that 10 years later, NASA would award a contract to a company to demonstrate a capability that would render irrelevant the three programs—SLS, Orion and Exploration Ground System—that the agency had been spending $3-4 billion a year on since 2011, I would have said you were nuts, but that’s what they did when they gave SpaceX an HLS contract,” says Jim Muncy, founder and principal of PoliSpace, an independent space policy consultancy.

But Starship is still in development. After two years and eight flight tests, the ship’s reusable upper stage has yet to reach orbit. In addition, for NASA’s Artemis Moon landings, Starship will need to be refueled in Earth orbit, a technology that has not yet been demonstrated. At least 15 Starships will need to be launched with fuel before the Starship HLS sets out for deep space.

“During Apollo, the pacing item was the lander, and it seems like we are on the same path,” says Wayne Hale, a retired NASA senior manager who oversaw the space shuttle program and later served as deputy associate administrator for strategic partnerships.

“I’m extraordinarily impressed by what SpaceX has done with their Starship, but on the other hand, it has yet to make it to orbit,” Hale says. “I know they keep saying, ‘Well, we blow things up and we learn a lot.’ I would like to learn a lot without blowing things up. And I’d like to get into orbit, which is not the hard part. Coming back from orbit is harder. Landing on the Moon is even harder, but probably the hardest thing that hadn’t been demonstrated yet is refueling that lander in low Earth orbit. They’ve got to pick up the pace, and they’ve got to start being more successful.”

Historically, the development time for a crewed spacecraft is 8-10 years. SpaceX’s Crew Dragon, which was contracted by NASA in 2012, flew astronauts for the first time in 2020. Work on the agency’s space shuttle—a far more complicated and capable system—began in 1972 and launched for the first time in 1981. Boeing started developing its CST-100 Starliner spacecraft at the same time as SpaceX, and conducted a crewed flight test in 2024, 12 years later. Boeing has more work ahead before Starliner is certified for operational crew rotation missions to the ISS.

Technical limitations and excessive development costs aside, SLS-Orion is the only system capable of sending astronauts to the Moon—the focus of not only the U.S. human space program but also efforts by other countries, including China.

The China National Space Administration has landed robotic probes on the Moon four times and is planning a multi-spacecraft study of the lunar south pole next year on the Chang’e 7 mission. NASA is eyeing the south pole for its Artemis III crewed landing, which would mark the return of U.S. astronauts to the lunar surface for the first time since Apollo 17 in 1972. The polar region has permanently shadowed craters that are believed to contain water ice and other volatiles of potential value for future space exploration and development. China has announced plans to launch a crew to the Moon before 2030 and establish a lunar research base at the south pole in partnership with Russia and other countries.

Details of the White House’s plans for NASA are expected later this month with the release of the full 2026 budget request. But one goal is clear: Land U.S. astronauts on the Moon ahead of a first touchdown by Chinese taikonauts, which could happen during Trump’s term.

“I don’t think that we should be in a race, necessarily, with the Chinese,” Hale says. “But the day that the Chinese land people on the Moon is going to be a really sad day, in my opinion, because they’ll be there before the next Americans are. I think the odds are in their favor.”

Aside from landing a U.S. crew before China does, the White House budget summary does not elaborate on what happens next, such as how to maintain a lunar presence, especially with SLS, Orion and Gateway earmarked for termination. Unlike the 1969-72 Apollo initiative, the Artemis program, which began during the first Trump administration, is intended to extend human presence from low Earth orbit (LEO) into cislunar space, seed economic development, expand scientific access and thwart potential Chinese claims on lunar resources.

Instead, the White House proposes to spend $1 billion on technologies to prepare for a crewed mission to Mars—a distant goal of the U.S. space program but the raison d’etre for SpaceX and its founder and CEO Elon Musk, a close Trump advisor. That level of funding appears inadequate for any near-term missions to Mars.

SpaceX is NASA’s top contractor, after the California Institute of Technology’s Jet Propulsion Laboratory, with contracts to fly astronauts to and from the ISS, develop and fly a Starship-derived lunar lander, and launch science and other NASA satellites on Falcon 9 and Falcon Heavy rockets. The agency also recently added Starship to its portfolio of launch services.

The proposed shifts come as NASA awaits its new administrator. Confirmation of Trump nominee Jared Isaacman, a billionaire technology entrepreneur who has twice chartered private space missions from SpaceX, is pending.

On April 30—two days before the administration released its budget summary—the Senate Commerce, Science and Transportation Committee voted 19-9 to advance Isaacman’s nomination to a vote by the full Senate. Four Democrats joined all the Republican committee members to support the nomination. On May 7, the White House nominated retired Air Force Col. Matt Anderson to serve as Isaacman’s deputy.

Ahead of the committee vote, Isaacman wrote in response to senators’ questions following his April 9 confirmation hearing that he had not reviewed the administration’s 2026 budget proposal, but that an approximate “50% reduction to NASA’s science budget does not appear to be an optimal outcome. . . . If confirmed, I will advocate for the agency’s priorities and the resources necessary to achieve them while ensuring that any organizational changes are thoughtful, mission-focused and grounded in the need to enhance—not diminish—NASA’s ability to deliver on the mission.”

U.S. Sen. Ted Cruz, who chairs the Senate Commerce, Science and Transportation Committee, repeatedly asked if Isaacman would “follow the law” by upholding congressional orders for NASA to focus on lunar exploration and development prior to a crewed mission to Mars, as proposed by Musk.

“Existing law directs NASA to establish a sustained human presence in cislunar space or on the Moon,” Cruz said. “Federal law explicitly calls the Moon a steppingstone to reaching Mars. In other words, our path to predominance in space begins with the Artemis missions. . . . Martian objectives . . . should not detract from the near-term objective of returning to the Moon first.” Isaacman repeatedly said he would follow the law.

If confirmed, Isaacman might be challenged to reconcile his commitment to the Artemis initiative with the Trump administration’s plan to speed up work on a human mission to Mars, the single area of growth in its budget plan for NASA.

“I don’t think the administration selected Jared Isaacman to just be a little more efficient at how NASA does things,” Muncy says. “I think he was brought in because he knows that you can do things fundamentally differently, and he also believes that the taxpayer deserves actual results instead of excuses. We’ve had excuses in space for so very, very long.”

A self-made billionaire, Isaacman left high school to work on computers full-time. At age 16, he formed his first company, which eventually became Shift4, a point-of-sale payment-processing firm. Isaacman later received a GED, became a private pilot and in 2011 founded another company, Draken International, which provides fighter-jet training to U.S. military pilots and defense contractors. That same year, he earned a bachelor’s degree in professional aeronautics from Embry-Riddle Aeronautical University.

In 2021, Isaacman chartered and commanded the first privately funded, all-civilian orbital spaceflight, paying SpaceX an undisclosed sum to fly him and three guests on the three-day Inspiration4 mission. He returned to space in September 2024 with three new crewmates on the five-day Polaris Dawn flight. In addition to traveling farther from Earth than any astronauts since the Apollo Moon program, Isaacman became the first private citizen to carry out a spacewalk.

During his confirmation hearing, Isaacman floated the idea that NASA could become financially self-sustainable. He later cited as an example the FAA’s Airport and Airway Trust Fund, which helps finance such projects as airport construction, safety improvements, air traffic control system upgrades and agency operations.

Isaacman’s interest in building the space economy runs counter to another White House budget proposal to reduce the number of crew and cargo flights to the ISS “significantly” ahead of its planned deorbit in 2030. The budget plan cuts $508 million from the current $3 billion ISS program, which covers station operations and transportation for crew and cargo.

Isaacman said during his hearing that NASA should “maximize the return taxpayers have invested in [the ISS] and use every bit of time we have to crack the code on the space economy and give commercial LEO destinations a fighting chance when they inevitably take over.”

The budget summary does not specify a funding level for the agency’s Commercial LEO Destinations program, another effort to leverage government funds with private investment to accomplish national goals. The point of the initiative is to establish one or more privately owned and operated space stations that can host NASA research and personnel after the ISS is decommissioned.

In addition to paring down the ISS program, the proposed budget cuts include:

• $2.3 billion from NASA’s space science portfolio, including elimination of the flagship Mars Sample Return effort. Instead, the Office of Management and Budget says the program goals “would be achieved by human missions to Mars.”
• $1.2 billion from Earth science programs, eliminating “climate-monitoring” satellites and restructuring the three-spacecraft Landsat Next constellation intended to map and monitor the planet’s natural resources.
• $1.1 billion from the Mission Support Directorate, which includes information technology services, agency center operations, facility maintenance, construction and environmental compliance and restoration activities.
• $879 million to phase out the SLS, Orion and Gateway programs. How that would affect designs for the SpaceX and Blue Origin landers is unknown. The Gateway includes modules and hardware from the European Space Agency, Japan, Canada and United Arab Emirates.
• $531 million from space technology programs, amounting to a 50% reduction.
• $346 million from NASA’s aeronautics programs—about one-third of its budget—including elimination of “climate-focused” green aviation.
• $143 million from Science, Technology, Engineering and Mathematics engagement, zeroing out the educational initiatives.

Rep. Grace Meng (D.-New York), ranking member of the House Appropriations Commerce, Justice, Science and Related Agencies Subcommittee that funds NASA, called the Trump administration’s proposed budget “shocking.”

“[The cuts] will decimate NASA’s research and education efforts and terminate funding for our nation’s dedicated scientists,” Meng wrote on the social media site X. “Rather than rooting out so-called government waste, this budget puts American leadership in science, technology and innovation at risk.”

Rep. George Whitesides (D.-Calif.)—a freshman legislator with deep roots in the space community as former chief of staff at NASA and CEO at Virgin Galactic—agreed, calling the nearly 25% cut to NASA “the biggest attack against the agency in recent history. . . . No spin will change the fact that this would end critical missions, dramatically scale back the workforce and risk our scientific leadership around the globe.”

“For human spaceflight, my immediate reaction is that the budget appears to essentially turn it over to SpaceX,” Hale notes. “Some may see that [as] a good objective, but it marks the end of the program of record and . . . the programmatic objective to return to the Moon to stay, exploit resources and build up infrastructure for the future.

“The question is: Is there a consensus on funding for civil space for NASA to continue, or is that going to change?” he says. “Any politician that comes in and says, ‘Hey, we’re going to do some great thing in space within one presidential term that may be different than what we had planned before’ doesn’t understand the problem.”