Scientists Rally Support for NASA as Appropriators Begin Markups

As Congress begins marking up the FY2026 appropriations bill for NASA, leaders of the space and earth science community are urging Congress to reject deep cuts proposed by the Trump Administration. NASA’s total budget would drop by $6 billion, 24.3 percent. The science budget alone is cut by 47 percent. At risk are NASA space and earth science missions large and small, some already operating, others still in development, many with international partners.

The Senate Appropriations Committee meets on Thursday to mark up three FY2026 appropriations bills including Commerce-Justice-Science (CJS), which funds NASA. The Trump Administration’s FY2026 budget request hits science agencies like NASA hard both with funding and workforce cuts.

NASA’s total budget would shrink from $24.8 billion to $18.8 billion and remain at that level, unadjusted for inflation, through 2030. NASA’s human spaceflight programs fare best, especially with the $10 billion provided in the reconciliation bill that President Trump signed into law on July 4.  By contrast, science, space technology and aeronautics don’t do very well at all.  Science and space technology both would be cut in half, aeronautics by a third. The total NASA civil service workforce has to drop from 17,391 Full Time Equivalents (FTEs) to 11,853 FTEs by October 1.

For months The Planetary Society (TPS) has been warning of the consequences of drastically cutting NASA’s science budget calling it a Dark Age for NASA Science. Yesterday it released a letter signed by all living former directors of the Science Mission Directorate (SMD) that was sent to both House and Senate appropriators.

Led by TPS Board Member and former astronaut John Grunsfeld, the letter outlines the impact not only on the U.S. and international science communities, but the U.S. science and aerospace workforces, America’s ability to counter Chinese space capabilities, and losing the “power of these programs to inspire and motivate bright minds.”

This proposed budget ends nearly all future investments for both new missions and advanced technology for science. It walks away from dozens of current, extraordinarily successful and productive science missions in extended operations on a combined budget that is only about three percent of NASA’s annual funding.

In closing, given the scale of the proposed cuts, their long-term consequences, and the potential loss of human knowledge and inspiration, we unanimously urge Congress to reject the proposed cuts to NASA’s budget.

The letter is signed by seven of the eight people who have led SMD since 1987: Len Fisk (1987-1993), Wes Huntress (1993-1998), Ed Weiler (1998-2004, 2008-2011), Al Diaz (2004-2005), Alan Stern (2007-2008), John Grunsfeld (2012-2016), and Thomas Zurbuchen (2016-2022). Mary Cleave, the first woman and first former astronaut to head SMD (2005-2007) passed away in 2023.  Grunsfeld, also a former astronaut, flew three of the five space shuttle missions that repaired the Hubble Space Telescope.

The seven former SMD Associate Administrators want Congress to keep SMD at its FY2025 enacted level. That $7.3 billion already is a reduction following two-years of agency-wide cuts due to the Fiscal Responsibility Act plus the effects of inflation. The FY2026 request is $3.9 billion.

SMD programs identified for termination in the budget request include satellites that are currently operating and sending back data, as well as spacecraft still in development.  Among the many operating spacecraft that would be turned off are the Chandra X-ray space telescope, Earth remote sensing satellites Terra, Aqua and Aura, and planetary exploration spacecraft far out in the solar system — New Horizons (which flew past Pluto and is now in the Kuiper Belt) and Juno (orbiting Jupiter).

The budget request would also terminate the OSIRIS-APEX mission that would reuse the OSIRIS-REX spacecraft that successfully brought back samples from the asteroid Bennu to make intensive studies of another asteroid, Apophis, after it makes a close-pass of Earth in 2029. The main spacecraft dropped off the samples in 2023, but it is still in space ready for another assignment and scientists chose Apophis as the new target. Understanding asteroids that could pose a threat to Earth — called planetary defense — has been a congressional priority for years.

Another planetary defense mission, NEO Surveyor, is funded in the request, but it is an earth-orbiting infrared telescope designed to locate and track asteroids, not visit them to do detailed analysis.

Despite President Trump’s interest in sending people to Mars — adding $1 billion for that — the budget request would end operations of two NASA spacecraft currently orbiting Mars (MAVEN and Mars Odyssey) and NASA’s participation in ESA’s Mars Express orbiter. It would also terminate development of the NASA-ESA Mars Sample Return Mission as well as NASA’s participation in ESA’s Mars rover, Rosalind Franklin.  The request would also cancel Helioswarm, a heliophysics mission that, among other things, would provide data on space weather to help protect astronauts from radiation exposure between Earth and Mars.

Many other science missions, including two that would study Venus for the first time in 30 years (VERITAS and DAVINCI), also are on the chopping block.  Acting NASA Administrator Janet Petro recently expressed a glass-half-full philosophy saying NASA will still be able to do great science with the not-quite $4 billion that remains, despite plummeting from $7.3 billion in just one year.

The Senate Appropriations Committee’s CJS subcommittee didn’t hold a hearing on NASA this year so Thursday’s markup will be the first indication of how far, if at all, they are willing to go to help the agency. The House Appropriations Committee also hasn’t held a NASA hearing. They postponed the markup they’d planned this week. No new date was set. FY2026 begins on October 1.