Climate and Earth-observing are systematically dismantled
The Earth Science missions proposed for cancellation monitor climate, carbon, or atmospheric composition: OCO-2 and OCO-3 (atmospheric CO₂), Aura (ozone layer), Atmosphere Observing System (aerosols), and others. The terminations impact both in-development projects and spacecraft in their extended missions. What they share is, broadly, a climate-science relevance.
Venus exploration is abandoned
The two Discovery missions selected in 2021, DAVINCI and VERITAS, as well as the U.S. contribution to ESA’s EnVision mission, would be eliminated. That represents NASA’s entire Venus portfolio. Even the modest Venus Technology line, used to prove out future instrumentation and hardware for Venus exploration, would be removed. No comparable full-target elimination appears for any other Solar System destination.
International-partner missions are disproportionately cut
Fifteen of the proposed terminations would break partnerships with foreign agencies serving as prime or co-leads, including ESA (Rosalind Franklin rover, Athena, EnVision, LISA, Mars Express), JAXA (XRISM, Solar-B), the Israel Space Agency (ULTRASAT), and the Korea AeroSpace Administration (CODEX). While some of these would amount to turning off an instrument on a spacecraft, many would abandon a key ally on a project that otherwise depends on major U.S. hardware or launch contributions to ensure a successful mission.
Extended missions are terminated despite sunk costs
Nearly half of the 53 cancellations are operating in their extended mission phase. These missions offer some of the highest “science per dollar” returns in NASA’s portfolio. By operating them past their original design lifetimes, NASA squeezes every available bit of science from them, returning huge value to taxpayers. Terminating them now would permanently wipe out years of priceless data to achieve savings measured in single-digit millions per mission, a fraction of total expenditures.
Artemis-adjacent and Mars-surface assets are preserved
Missions with a direct line to Artemis architecture (instrumentation for lunar missions, VIPER, LRO) or Mars surface operations tied to future human exploration (Mars 2020 (Perseverance), MRO) are absent from the proposed terminations. Notably, however, Perseverance would see its operating funds slashed in half, forcing a significant reduction in scientific productivity. Multiple Mars missions are still slated for cancellation, including Mars Odyssey. MAVEN, not present on this list, suffered a hardware failure last year that has almost certainly ended the mission.
Science missions nearing launch are funded
NEO Surveyor, Dragonfly, and the Nancy Grace Roman Space Telescope are all funded. Notably, these missions were all started in prior administrations and are currently in their peak development phase, with launches scheduled in the next two years.
Research funding is cut across the board
Research funding, the lifeblood of the scientific community that both maintains the professional scientific workforce and funds training of future scientists, suffers cuts across the board. It is difficult to assess the full scope of cuts applied to basic scientific research, as the FY 2027 budget request does not report baseline amounts from prior years, another dramatic departure from past budget documents presented to Congress. The only reliable numbers we have are from 2024. Those amounts theoretically should be similar to those spent in 2025, given that the entire fiscal year was under a continuing resolution that kept funding flat.