Senate Appropriators Join House in Opposing Trump’s NASA Cuts

The Senate Appropriations Committee is joining its House counterpart in opposing President Trump’s proposal to deeply cut NASA’s budget and modify the Artemis program. From human spaceflight to science to space technology to aeronautics to STEM engagement, the committee’s FY2026 Commerce-Justice-Science (CJS) bill essentially maintains NASA’s current funding and existing programs, although there is no mention of the Mars Sample Return mission. The House Appropriations CJS subcommittee similarly keeps NASA funding steady. While there are some differences, overall both sides of Capitol Hill appear aligned to preserve NASA. If enacted, the outcome will be far better than the Administration’s plan to cut NASA by 24.3 percent.

Unlike past years, neither the Senate nor the House appropriations committees held hearings on NASA’s budget request. The committee markups over the past week-and-a-half are the first opportunity to discover whether Congress agrees with the Trump Administration’s proposal to cut NASA by $6 billion, from $24.8 billion to $18.8 billion, and keep it there through 2030 with no adjustment for inflation.

The Trump proposal calls for roughly 50 percent cuts to science and space technology and  one-third to aeronautics. NASA’s human spaceflight program fares the best, but even there operations of the International Space Station would be reduced and the future of the Artemis program beyond Artemis III, the mission intended to put American astronauts on the lunar surface for the first time since 1972, is unclear. The Administration wants to terminate the Space Launch System (SLS) rocket and Orion spacecraft that take astronauts to lunar orbit and replace them with commercial alternatives even though no such alternatives exist yet. It also wants to kill the Gateway lunar space station being built with Europe, Canada, Japan, and the United Arab Emirates.

The House CJS subcommittee approved their bill on July 15. The full committee will take it up this coming Thursday. The full Senate appropriations committee approved their version on July 17 after an unrelated issue — the location of a new FBI headquarters building — derailed consideration on July 10.

What’s clear is that on a bipartisan, bicameral basis, Congress supports NASA and wants to keep its total funding level where it is now. The House subcommittee approved the exact same amount as FY2025 (not adjusted for inflation): $24.838 billion. The Senate committee adds $61 million raising the total to $24.900 billion. The committees’ actions are just steps in a lengthy process, but at least progress is being made.

The two chambers don’t agree on everything — the House allocates more to exploration and less to science and NASA’s other accounts– but they both want to maintain NASA as an agency conducting leading-edge science, technology, aeronautics and exploration.

The House CJS subcommittee released the text of their bill and a summary, but not the report that provides details. It typically becomes available after full committee markup. The full Senate Appropriations committee has completed work so the text, summary, and report are all posted.

The Senate committee’s report includes tables that highlight programs of special interest, but they are only examples.  For science, the table specifies amounts for two Earth Science, four Planetary Science, five Astrophysics and two Heliophysics missions, but the report itself goes into much more detail. Overall, they keep the science budget roughly at its current level of $7.3 billion instead of the $3.9 billion proposed by the Administration.

The Administration wants to terminate 55 operating earth-orbiting and deep space missions that continue to send back data even though they are beyond their original lifetimes. The committee rejects the Administration’s plan because it is driven by budget pressures, not scientific value. NASA routinely convenes “Senior Reviews” where scientists evaluate whether a spacecraft continues to provide data sufficient to justify the cost to operate it. The committee wants that process to determine which missions are terminated, not the White House Office of Management and Budget (OMB). The extensive list of programs the committee specifies for continuation includes the Chandra X-ray telescope, the Terra, Aura and Aqua earth science satellites, the New Horizons and Juno planetary missions.

The committee also highlights the importance of “NASA upholding its commitments to our international partners.” Many if not most NASA science missions are done in partnership with the European Space Agency (ESA), the Japanese Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA) and many other agencies and countries. Two ESA-led programs in development — the Laser Interferometer Space Antenna (LISA) gravitational wave detector and ExoMars Rosalind Franklin Mars rover — are specifically cited as programs the committee wants continued.

One that’s not mentioned, however, is the NASA-ESA Mars Sample Return mission. Considerable cost growth and schedule delays plagued MSR in recent years. This committee raised the alarm in 2023 leading NASA to pause the program and look for new ideas. As the Biden Administration came to an end in January, NASA’s leadership said they’d leave it to the next administration to decide how to proceed. The program is zeroed in the President’s budget request, which says NASA will “pivot to lower-cost, competitively selected Mars science missions that can complement our long-term human exploration goals.”

For human spaceflight in the Exploration and Space Operations accounts, Senate appropriators disagree with much of the Trump Administration’s plan.  They do not want to reduce the number of crew and cargo flights to the International Space Station, terminate SLS/Orion after Artemis III, or kill the Gateway lunar space station. The $10 billion for NASA in the reconciliation bill also rejects the Trump plans, adding money for ISS, SLS, Orion and Gateway along with other human spaceflight programs. That money is in addition to whatever Congress appropriates through the regular appropriations process. The reconciliation bill, officially the “One, Big Beautiful Act,” specifies years over which funding must be put under contract, or “obligated,” for specific programs, but not by year so it is not possible at this point to know how much will be for FY2026 alone.

Senate appropriators are concerned about whether the 2027 date for returning American astronauts to the lunar surface is achievable. They add funding to accelerate development of the commercial Human Landing Systems (HLS) to get astronauts from lunar orbit down to and back from the surface. SpaceX and Blue Origin are under contract to build those systems through public-private partnerships. They design, develop and own the systems. NASA purchases services from them as it does for  commercial crew vehicles that ferry astronauts to the ISS. SpaceX is under contract to NASA to put astronauts on the lunar surface in 2027 on Artemis III and again for Artemis IV, with Blue Origin doing it for Artemis V at the end of the decade and the two would compete for future missions. But getting American astronauts back on the Moon before China puts taikonauts there, which it plans to do by 2030, is a congressional priority.

The Senate committee does agree with the Trump administration’s interest in accelerating efforts to send people to Mars.  The Trump proposal includes $1 billion to that end. The Senate bill “strongly supports” the goal and “reducing costs through the use of commercial innovation, fixed-price development contracts, and follow-on procurement of commercial services.” It directs NASA to give priority to advancing the development of commercial systems that can land “human-class cargo-and eventually crew-on Mars” with “the aim of launching an initial system demonstration during the 2026 Earth-Mars transfer window.” They don’t specify how much funding they’re providing for that, however.  The House subcommittee allocates $9.7 billion for Exploration, $2 billion more than the Senate committee, but details on how it wants the money spent aren’t available yet.

The Senate committee also agrees with transferring the Commercial Lunar Payload Services (CLPS) program from the Science Mission Directorate (SMD) to the Exploration Systems Development Mission Directorate (ESDMD) and the fission surface power program from the Space Technology Mission Directorate (STMD) to ESDMD.

Nuclear fission surface power is for operations on the surface of the Moon and Mars and is supported by the Administration and Congress. But the Administration wants to terminate NASA’s effort to develop nuclear propulsion for spacecraft to send people and cargo to Mars. Nuclear electric propulsion (NEP) and nuclear thermal propulsion (NTP) have been under development for a long time. For many years Congress has appropriated $110 million annually for NTP (conducted at Marshall Space Flight Center) and the Senate bill continues that while requiring NASA to submit a strategy for development of NTP and NEP.

Senate appropriators also come out in strong support for NASA’s Science, Technology, Engineering and Math (STEM) education programs. As it did in Trump’s first term, the Administration wants to terminate STEM. Congress rejected it then and are poised to do it again now. The Senate committee funds Space Grant, EPSCoR, MUREP and the “Next Generation STEM Project” for a total of $148 million in its usual line item “STEM Engagement.”  The House subcommittee no longer funds “STEM Engagement,” but includes money for Space Grant and EPSCoR in the Safety, Security, and Mission Services (SSMS) account.

Overall, House and Senate appropriators are on a path to fund NASA in contradiction to the Trump Administration’s plans, and that doesn’t even include the $10 billion in the reconciliation bill that is separate from appropriations.

At the same time, OMB is testing the limits of executive power. It is no sure bet NASA will be allowed to spend everything Congress allocates unless Congress pushes back, which it hasn’t done to date.

The Senate Appropriations Committee had a lengthy debate on July 17 about its constitutional authority under Article I just hours after the Senate agreed to rescind (take back) money they had appropriated in FY2025 for foreign aid and the Corporation for Public Broadcasting (PBS and NPR). Only two Republicans, appropriations committee chair Sen. Susan Collins (R-Maine) and Sen. Lisa Murkowski (R-Alaska), another appropriations committee member, voted against the bill, which passed 51-48. Although appropriations bills require 60 votes to pass in the Senate, rescissions are a different type of legislation and only 51 votes are needed. As committee members pointed out, in the Senate it is easier to “claw back” money than to appropriate it in the first place.

OMB Director Russell Vought has made clear that was just the first rescission bill he plans to send to Congress. He also said the historically bipartisan appropriations process “has to be less bipartisan.”

Getting appropriations bills passed by Congress and signed into law has been a challenge in recent years. None cleared Congress for FY2025. The government is operating under a year-long Continuing Resolution. For the future, it appears that even passing appropriations bills is no longer a guarantee about how much money any agency will be able to spend, with the possibility of partisan rescission packages hanging over every dollar.

House members are already raising concerns about whether NASA is spending FY2025 funding as appropriated or beginning to close down programs as though the budget request was adopted. Rep. Zoe Lofgren (D-California) and Rep. Valerie Foushee (D-North Carolina), ranking members of the House Science, Space, and Technology Committee and its space subcommittee respectively, sent a letter to Acting NASA Administrator Sean Duffy on July 17, warning of “dire consequences to U.S. leadership in space” if he impounds FY2025 money. Foushee led a bipartisan group of more than 60 House members in writing another letter to Duffy the next day with similar concerns.

The lack of a Senate-confirmed NASA Administrator adds to the agency’s challenges in making its case to the Trump  Administration and Congress. Duffy is NASA’s second Acting Administrator this year and his main responsibility is serving as Secretary of Transportation. Trump withdrew his original nominee, Jared Isaacman, after a falling out with Elon Musk, who advocated for Isaacman.  When Trump will nominate someone else is anyone’s guess.

The biggest obstacle for NASA and all other government agencies, however, is the sanctity of the appropriations process under the Constitution. Unless Congress on a bipartisan basis insists that the Executive Branch spend money the way Congress appropriates it, as required by Article I, Section 9, Clause 7,  agencies across the government will have no assurance that whatever money is appropriated will actually be available for them to spend.