NASA budget proposal boosts human exploration — at expense of science

The White House on Friday released its fiscal year 2026 discretionary budget request, proposing a dramatic reduction in NASA’s overall funding from about $25 billion to $18.8 billion, or about 25 percent. But not all programs will be affected equally.

The discretionary or “skinny” budget is akin to a blueprint and is an early step in the process. It could change as it moves through the legislature. But the initial proposal props up NASA human space exploration while casting a dark shadow over the space agency’s science and other programs. The Mars Sample Return mission, Space Launch System rocket, Orion capsule, and Gateway space station all face impacts from cuts to their respective programs.

“This proposal includes investments to simultaneously pursue exploration of the Moon and Mars while still prioritizing critical science and technology research,” Janet Petro, whom President Donald Trump in January appointed acting NASA administrator, said in a news release. “I appreciate the president’s continued support for NASA’s mission and look forward to working closely with the administration and Congress to ensure we continue making progress toward achieving the impossible.”

Shift4 Payments CEO and private astronaut Jared Isaacman, Trump’s pick to lead NASA, has also emphasized simultaneous missions to the Moon and Mars, though he said a major cut to science programs “does not appear to be an optimal outcome.”

Isaacman’s nomination advanced to the full Senate on Wednesday after a 19–9 committee vote.

Meanwhile, a coalition of space science groups has rallied against the proposed cuts and urged Congress to fully restore science funding.

“Slashing NASA’s budget by this much, this quickly, without the input of a confirmed NASA administrator or in response to a considered policy goal, won’t make the agency more efficient — it will cause chaos, waste the taxpayers’ investment, and undermine American leadership in space,” The Planetary Society said in a statement Friday.

Human exploration gets a boost

Despite the overall reduction, NASA human space exploration initiatives would receive a $647 million increase in the proposed budget. The White House wants to allocate more than $7 billion for lunar exploration and direct $1 billion in new investments to “Mars-focused programs.”

Per the budget document, the added funding “ensures that America’s human space exploration efforts remain unparalleled, innovative, and efficient” while focusing on “beating China back to the Moon and putting the first human on Mars.”

Both Trump and SpaceX CEO Elon Musk — from whom Isaacman has purchased four private spaceflight missions — have publicly pushed for NASA to focus on the Red Planet over the Moon. Trump in his inauguration speech vowed to land Americans on Mars but made no mention of Earth’s satellite, while Musk has said that “stopping at the Moon simply slows down getting to Mars.”

Isaacman during an initial confirmation hearing in April said he would “prioritize sending American astronauts to Mars” and that NASA would develop the capabilities to return to the Moon “along the way.” Later, though, he expressed a commitment to follow federal laws directing NASA to use the Moon as a “stepping stone” toward Mars.

Elected officials, including Senator Ted Cruz (R-Texas), chair of the Senate Committee on Commerce, Science, and Transportation, have urged Isaacman to stay the course on lunar initiatives such as the Artemis program.

Major cuts target science, technology and legacy systems

While human exploration receives a bump, several NASA programs — including Artemis — face substantial impacts under the discretionary budget. The proposal calls for reductions of:

• $2.265 billion for space science.
• $1.134 billion for mission support.
• $1.161 billion for Earth science.
• $879 million for legacy human exploration systems.
• $531 billion for space technology.
• $508 million for the International Space Station (ISS).

Perhaps most notable is the White House proposal to phase out SLS and Orion — both of which are significantly over budget — after the Artemis 3 lunar landing, scheduled for mid-2027.

Estimates on launch costs for the SLS vary. But the White House estimated it at $4 billion and described it as “grossly expensive and delayed.” Instead, the administration proposed funding a “program to replace SLS and Orion flights to the moon with more cost-effective commercial systems that would support more ambitious subsequent lunar missions.” Lunar Gateway — a small orbital outpost designed to support future SLS and Orion missions — is on the chopping block as well.

The Mars Sample Return mission, which has also faced cost overruns, would be terminated entirely under the proposal. The White House argues the return of samples to Earth, considered a key space science goal, could be “achieved by human missions to Mars” instead of the complex architecture NASA envisions. The space agency has requested proposals from the industry to accelerate a return.

ISS operations would also be affected by a proposal to reduce crew size, onboard research, and the cadence of flights to the orbital laboratory. Research would instead be directed toward “efforts critical to the moon and Mars exploration programs.”

Further reductions could impact what the document characterizes as “low priority” climate satellites, “failing” space propulsion projects, and “woke” STEM programming. Cuts to mission support, meanwhile, would “streamline the workforce,” the administration said.

The outlook

These cuts align closely with what Ars Technica reported in April after a draft of the proposal was leaked. Certain suggestions, such as those affecting programs that generate a significant number of jobs, could face pushback from Congress. The Planetary Society warned the “destructive” proposal could lead to “widespread terminations.”

Read more: NASA faced with massive budget cuts in White House proposal

The group also criticized the document for hampering “American leadership in space science, exploration, and innovation” and straying from “Trump’s own stated goal that America must ‘lead the way in fueling the pursuit of space discovery and exploration.’”

Soon, Isaacman — who awaits a final vote on his confirmation — will be in the eye of this storm. Notably, The Planetary Society and other industry groups have expressed support for Isaacman, suggesting he is viewed as someone who will advocate for preserving science funding.

The White House contends that private companies will be able to take on much of the science and program development that NASA does. But some in the industry believe that is wishful thinking.

“These cuts would damage a broad range of research areas that will not be supported by the private sector,” the American Astronomical Society said in a statement. “Without robust and sustained federal funding, the United States will lose at least a generation of talent to other countries that are increasing their investments in facilities and workforce development. … These proposed cuts will result in the loss of American leadership in science.”

This story first appeared on FLYING.