Many ships have tried to reach the floating tongue of Thwaites Glacier—a 130-kilometer-wide conveyor belt of ice that slides off West Antarctica’s coast and splinters into the sea. Thwaites is rapidly destabilizing, and precise mapping of the seafloor and ocean currents surrounding it are urgently needed to know how much damage the crumbling glacier and resulting sea-level rise could do to coasts worldwide. Only one vessel—the U.S. research icebreaker Nathaniel B. Palmer (NBP)—has successfully penetrated the area’s phalanx of sea ice and billion-metric-ton icebergs to reach a critical location on Thwaites, widely considered the world’s most dangerous glacier. The NBP has made about 200 research cruises to Antarctica in the past 30 years, in many cases reaching places never before visited. But if the Trump administration has its way, this will all come to an end in October.
The NBP’s expeditions along remote parts of the Antarctic coast have gathered voluminous data that are critical to U.S. interests. If the Thwaites Glacier were to implode, it could raise the average global sea level by 65 centimeters, and it could potentially trigger wider Antarctic ice sheet collapse that could raise global sea level by more than three meters. Marine science shows that a disproportionate brunt of that rise would inundate the Gulf of Mexico and eastern U.S. coasts. Frequent measurements in Antarctica’s remote locations are needed to project how quickly this might happen. Expeditions also monitor marine ecosystems that are rapidly shifting as a result of climate change and affecting the large commercial fisheries in surrounding waters.
Yet Antarctic science experts and officials told me that the administration is imposing such severe budget cuts on the U.S. National Science Foundation (NSF) that the organization has no realistic option but to terminate its lease for the NBP after 30 years. The U.S. is “losing the only research [icebreaker it has] in the Southern Hemisphere,” says Michael Jackson, the NSF’s former section head for Antarctic sciences, who left in December. A replacement vessel—if one is even funded—“will probably take 10 years to build,” he says.
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This latest move caps what feels like a major U.S. retreat from Antarctica, says Theodore Scambos, a polar glaciologist at the University of Colorado Boulder. For 27 years, the U.S. had operated two research icebreakers in the region. But in 2024 NSF dropped its lease for the smaller of the two craft because of budget shortfalls. That and the impending loss of the NBP marks “a general decline of America in the science and exploration fields,” Scambos says. “And I hate that.”
This loss will have widespread consequences, according to a wide range of scientists, logistics experts, former NSF officials and former diplomats interviewed for this story. It will hamstring U.S. influence in the Antarctic at a time when geopolitical competition and resource exploitation are intensifying in the region. It will also undermine scientists’ ability to monitor rapid changes in Thwaites and other remote areas—at the very moment climate impacts on the continent are accelerating.
Researchers first learned of the NBP’s situation on May 30, when the Trump administration released its full fiscal year 2026 budget request for NSF to Congress. The termination was buried in a single sentence on page 102 of the 222-page document. The budget request also stipulated a 70 percent funding cut for polar science research projects overall. “None of us saw that coming,” says Patricia Yager, a polar marine biologist at the University of Georgia, who called the move “shocking.” In response to a request for comment from Scientific American, an NSF spokesperson confirmed via e-mail that NSF had proposed terminating the lease of the NBP in Trump’s 2026 fiscal year budget request but provided little additional information.
Nathaniel B. Palmer breaking sea ice in the Ross Sea.
Michael Van Woert/NOAA NESDIS
Although the U.S. Coast Guard has three icebreakers—Polar Star, Healy and the newly commissioned Storis, a former commercial icebreaker—none can fill NBP’s role. Healy is continually committed to Arctic duties; sending it to Antarctica and back to do even a single day of scientific work would require 60 days of travel. Storis, which has a troubled history, will also be used in the Arctic. And Polar Star is simply not equipped for the kind of research the NBP does.
“The Palmer is the most amazing research tool that we have; there’s nothing like it anywhere in the world,” Yager says. It can plow through meter-thick sea ice at three knots with little more than gentle side-to-side rocking. And it can remain at sea for 65 days, a vital capability given that a round trip to Thwaites takes nearly two weeks from the nearest port. Waiting for vast rafts of sea ice and icebergs to shift and open a passage can add many more days.
When the NBP is in Antarctic waters, it continuously collects data. Multibeam sonar captures a three-dimensional map of the seafloor, revealing features such as undersea canyons that influence the stability of coastal glaciers. Another sonar system traces sediment layers below the seafloor, which can provide important records of past climate periods. Even in rough seas and high winds, the ship’s dynamic positioning system allows it to hover within a few feet of its intended location while technicians do the delicate work of collecting sediment cores or piloting remote-operated submersibles on the seafloor.
The NBP can carry and launch two helicopters, which proved decisive during a 2010 cruise, allowing researchers to leapfrog over impassable sea ice and install instruments for monitoring crustal movements and glacial retreat as far as 200 kilometers away.
Box-coring operations from the fantail of the Nathaniel B. Palmer icebreaker.
Michael Van Woert/NOAA NESDIS
The impending loss of the NBP means five Antarctic missions, slated for October 2025 through April 2026, now hang in limbo. The NSF is scrambling for ways to salvage at least some of them. For example, the agency might send the University of Alaska Fairbanks’s Arctic research vessel Sikuliaq all the way down to Antarctica in January to perform a major ecological survey that has been conducted annually since 1999. The survey covers 2,000 kilometers along the Antarctic Peninsula’s coast and out past the lip of the continental shelf. It measures the abundance of krill and phytoplankton—which anchor the region’s ecosystem—and monitors deep ocean currents. In recent decades this survey has revealed important changes in ocean mixing that have caused the winter sea ice season in this relatively temperate section of Antarctica to shorten by roughly 100 days a year.
But the Sikuliaq is already in high demand in the Arctic, for up to a dozen expeditions per year. And compared with the NBP, it has fewer berths for scientists, can spend fewer days at sea and has more limited ice-breaking capabilities—effectively excluding it from Thwaites and other heavily iced sections of the Antarctic coastline.
A few other countries have research icebreakers, including the U.K., Germany, Australia, South Korea and China. It is possible that a couple U.S. researchers could occasionally find ride-along spots. But that may not advance U.S. research priorities, Scambos says: “You’re not going to get somebody else’s icebreaker to bring you and 20 of your colleagues and undertake a major mission that has U.S. research interest behind it.” The NSF spokesperson stated that the agency “has started the process to identify vessels and partnerships to continue support of marine science.”
A new icebreaker that would eventually replace the NBP is in early design stages, but it would take a decade to build. The work on this new Antarctic research vessel has been moving slowly for a variety of reasons, even prior to the start of the current Trump administration. The NSF spokesperson stated that the agency “has paused source selection activities” for the next stage of development.
Since the 1950s the U.S. has maintained a larger scientific presence on the Antarctic continent than any other nation, by way of research stations, ships, remote air transport and exploratory teams that drive vehicles in long traverses across the ice sheet. For now, NSF plans to try to keep operating the three U.S. land bases in Antarctica—the Palmer, McMurdo and Amundsen-Scott South Pole stations—because the harsh environment would cause them to rapidly deteriorate if they were not staffed.
But spending an ensuing decade without a research icebreaker could have major geopolitical consequences. Antarctica is Earth’s largest remaining territory not unilaterally controlled by any particular nation. The U.S. has long backed the Antarctic Treaty, under which nations set aside any territorial land claims they’ve made and reserve the continent for scientific research. If international commitment to the treaty ever faltered, however, nations might pursue territorial claims on the continent, and those claims would be bolstered by having maintained research stations, communications hubs, deep water ports and air transport and driving routes. “Operations and logistics are 100 percent necessary for U.S. national security interests,” says William Muntean III, a former senior adviser for Antarctic affairs and a deputy representative for the U.S. State Department to the annual Antarctic Treaty Consultative Meeting.
The scientific research conducted there is a fundamental part of that equation. “In the Antarctic Treaty System,” Muntean says, “knowledge is what equals power.” That’s because the rules of play for Antarctica and its surrounding seas are constantly negotiated and monitored by more than two dozen countries with research stations there—and any negotiations become especially heated when it comes to resource extraction. For years commercial vessels have plied the coastal seas for Antarctic toothfish (sold in restaurants as “sea bass”) and krill. The U.S. and a handful of other countries have sought to establish several marine protected areas around the continent where fishing would be prohibited, but they have encountered resistance from Russia and China. Negotiations often hinge on data collected from research vessels, such as those that document changes in ecosystems. In this way, Muntean says, “knowing what is actually happening in Antarctica gives a country the ability to then influence” what happens.
Right now the NBP remains moored at the main pier in Punta Arenas in southern Chile—its standard departure point for Antarctica. The ship’s fate is on hold until early September, when Congress returns from recess. “The budget request is always just a policy document,” says Alexandra Isern, a former assistant director of the NSF. In the NSF’s pending request, she says, the Trump administration is putting “a line in the sand” for what it wants.
Funding bills that were sitting in Congress before recess add confusion. Senate bill 2354, which passed out of the Appropriations Subcommittee on Commerce, Justice, Science and Related Agencies in mid-July, appears to restore full funding to the NSF. The corresponding House bill restores roughly two thirds of the proposed cuts. Isern says “members [of Congress] are big supporters of the Antarctic program,” but neither of those bills mentions the NBP or the new icebreaker intended to replace it. Jackson fears that Congress will cave to pressure from the Trump administration and neither the NBP nor the other polar research funding will be saved.
In the meantime, polar researchers across the U.S. continue to prepare for science missions that may or may not happen. Some have already shipped their scientific gear south to Chile in case their cruise happens after all. Others will have to do so in the coming weeks, before Congress returns.
Amid the uncertainty, Oscar Schofield, a biological oceanographer at Rutgers University, sees a clear message. The administration is already stripping climate data from government websites, preparing to halt EPA regulation of carbon dioxide emissions and quietly discussing plans to scuttle a state-of-the-art NASA satellite that monitors carbon dioxide—allowing the spacecraft to burn up in the atmosphere. Canceling the NBP, he says, looks like “a political decision of not wanting to support climate change research.”
In this decision, Schofield sees an important lever of soft power being abandoned. “Since World War II,” he says, “there was always a strong belief that if the U.S. had the strongest scientists and the strongest engineers, it would serve national security.” Those generational investments, he says, are now being undone.
