Trump’s FY2026 NASA Budget: 5 Major Cuts and Impacts

If enacted as proposed, the White House’s fiscal year 2026 budget would slash NASA’s funding by nearly 25 percent—from $24.8 billion to $18.8 billion—delivering the smallest real NASA appropriation since 1961. Beyond headline numbers, this proposal targets core programs and advanced technologies that underpin America’s long-term ambitions for lunar bases, crewed Mars missions, and Earth science leadership.

1. Halving Robotic Science and Technology Development

Impact: Robotic missions and in-space demonstrations are slated for a 50 percent budget cut, dropping from roughly $7 billion to $3.5 billion in FY2026.

• Flagship planetary projects like Europa Clipper and Dragonfly rely on technology maturation funds for high-gain antennas, Ka-band radios (data rates up to 264 Mbps), and advanced power systems (up to 33 kW solar arrays). A 50 percent reduction stalls these upgrades.
• SmallSat and CubeSat initiatives—critical for rapid prototyping of atmospheric sensors, ISRU experiments, and autonomous navigation software—would see fewer flight opportunities, delaying commercial partnerships under NASA’s Venture-Class Acquisition of Dedicated and Rideshare (VADR) program.

2. Retiring SLS and Orion After Artemis III

Current Status: The Space Launch System (SLS) Block 1 rocket delivers 95 metric tons to LEO at an estimated cost exceeding $4 billion per launch. The Orion spacecraft, massing 25 metric tons fully fueled, provides deep-space life support for four astronauts.

Budget Proposal: Two additional Artemis missions (Artemis II crewed lunar flyby in 2026, Artemis III lunar landing in 2027) would proceed, after which SLS and Orion funding would drop to zero. Future human missions would rely solely on commercially procured vehicles.

“While reusable systems like Starship HLS promise lower marginal costs—potentially under $100 million per flight—they lack flight heritage beyond orbital hops,” notes Dr. Elena Musgrave, space systems engineer at Orbital Dynamics Inc.

3. Zeroing Out Nuclear Propulsion Research

Background: Nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) offer specific impulses (Isp) of 800–900 seconds and 3,000–5,000 seconds respectively, compared to ~450 s for chemical rockets. The DRACO (Demonstration Rocket for Agile Cislunar Operations) program—a NASA–DARPA partnership—aimed to ground-test a 1 MWth reactor with a 25 kN thrust class engine.

Proposed Cut: All $120 million in FY2024 NTP/NEP funding would be eliminated. This undercuts work on the Nuclear Cryogenic Propulsion Stage (NCPS) and follow-on reactor development—technologies considered critical for heavy cargo transport to Mars with 30 percent mass savings.

4. Terminating Key Robotic Science Missions

Targets: At least 19 currently operating missions, totaling over $12 billion in sunk investment and costing NASA less than $300 million annually to operate, would be decommissioned. Highlights include:

• Juno: 3,600 kg spacecraft in polar orbit around Jupiter since 2016, powered by a 400 W RTG, carrying a 352 kg science payload for magnetospheric and gravity-wave studies.
• New Horizons: 478 kg Pluto flyby and Kuiper Belt explorer, now heading toward interstellar space with a 200 W RTG and 30 kbps uplink rate at ~50 AU.
• Chandra X-ray Observatory: Flagship high-resolution imaging down to 0.5 arcseconds, probing black-hole accretion disks and galaxy clusters—no replacement until late 2030s.
• OSIRIS-REx: Now on OSIRIS-APEX to asteroid Apophis in 2029, providing sample return dynamics and near-Earth object characterization.

5. Scaling Back International Space Station (ISS) Operations

Budget Reduction: A 26 percent cut in ISS operations and crew/cargo services reduces annual funding from ~$3 billion to ~$2.2 billion.

• Planned crew of seven astronauts cut to four, slashing on-orbit research time from ~5,000 crew hours/year to ~2,800 hours.
• Cargo flights drop from eight to five per year, limiting resupply of cold-stowage freezers, microgravity research racks, and LIFE (Laser In - Flight Experiment) modules.
• Commercial LEO stations (Axiom, Starlab) face a longer gap before ISS retirement in 2030, creating a potential research blackout—ceding primacy in low-Earth orbit to China’s Tiangong.

6. Draining Human Health and Performance Research

Human Research Program (HRP) funding plunges from $151 million to $40 million in FY2026. Critical studies at NASA’s Space Radiation Laboratory and bed-rest analogs at Charleston’s Clinical Center—which quantify bone demineralization (1–2 percent/month), cardiovascular deconditioning, and neurobehavioral risks—will be curtailed.

“Reducing HRP by three-quarters jeopardizes our ability to lower mission‐critical risks from high to medium by the 2030s,” warns Dr. Rachel Chen, lead physiologist at the Janssen Space Biomedicine Lab.

Implications for International Collaboration

The proposed budget halts U.S. contributions to ESA’s Rosalind Franklin rover (ExoMars), EnVision Venus orbiter, LISA gravitational‐wave observatory, and ARIEL exoplanet mission. NASA’s $339 million commitment for throttleable descent engines and RTG heaters on ExoMars now appears in jeopardy, straining a partnership only recently restored after Russia’s ExoMars withdrawal.

Commercial Sector Response and Innovation Opportunities

While SLS and Orion face the axe, commercial providers see opportunity. SpaceX’s Starship HLS, with 150 metric tons to LEO and fully reusable stainless-steel architecture, claims launch costs under $50 million. Blue Origin’s New Glenn and Northrop Grumman’s OmegA are courting lunar cargo and habitat modules under revised procurement strategies.

Expert Opinions on Budget Rebalancing

1. Sen. Ted Cruz (R-Texas): “We must preserve SLS, Orion, and Gateway to maintain U.S. leadership; commercial efforts cannot replace heavy-lift heritage overnight.”
2. NASA Administrator Bill Nelson: “Robust science and technology programs are the bedrock of exploration; severe cuts risk ceding strategic advantage to China and ESA.”
3. Casey Dreier, Planetary Society: “Defunding mature missions that cost NASA 1–2 percent annually is penny-wise, pound-foolish. We lose decades of scientific return.”

Technical Deep Dive: The Future of Nuclear Propulsion

NTP systems, using uranium-based hexagonal fuel elements and hydrogen coolant at ~2,500 K, could halve cislunar transit times. NEP concepts pair compact fission reactors (50–100 kWe) with ion thrusters (Xenon propellant at 60 mN thrust, Isp 3,000 s) for flexible cargo transport. Without sustained funding, companies like BWX Technologies and Westinghouse face layoffs, and USAF’s space nuclear mission applications will stall.

Conclusion: The FY2026 budget proposal delivers the deepest cuts in NASA’s 63-year history. While lawmakers may restore key elements—in March 2025 the Senate Appropriations Committee added $2.5 billion back—the long list of cancellations underscores a tectonic shift toward commercial reliance. The ultimate outcome will shape whether NASA can maintain continuous human presence in deep space or relegates itself to minimal safe‐operations mode until technology matures independently.