WASHINGTON — The Trump administration's fiscal 2027 budget request asks Congress to cut NASA funding by 23% and reduce the agency's science programs by 46%. Congress rejected a similar 2026 NASA funding proposal in January.

According to an analysis by the nonprofit Planetary Society, the proposal would cancel 53 science missions and reduce funding for others. Projects with Jet Propulsion Laboratory involvement targeted for cuts include the Mars rover exploring an ancient river delta and a mission to orbit Venus, the analysis found.

The Jet Propulsion Laboratory has led innovation in space science and technology for decades from its La Cañada Flintridge campus. The administration previously defunded the laboratory's Mars Sample Return mission and has shifted its focus toward lunar exploration and away from the type of scientific work the lab executes.

In the budget request, NASA Administrator Jared Isaacman wrote that the agency was "pursuing a focused and right-sized portfolio" for its space science missions to align with federal cost-cutting goals. He wrote that the budget "reinforces U.S. leadership in space science through groundbreaking missions, completed research, and next-generation observatories."

Rep. Judy Chu said the proposal creates "enormous chaos and uncertainty in the meantime for critical missions, the scientific workforce, and long-term research planning." She said the programs marked for cancellation or cutbacks support thousands of jobs at JPL and other centers. "JPL cannot afford to lose more of this expertise," Chu said.

According to two former staffers, the lab has experienced steady employee departures in recent months, and remaining employees have sought outside funding, sold technology to companies, and increased productivity to maintain operations. A former JPL employee said, "If we're not doing science, then what are we doing?"

Two JPL projects involving Venus appear slated for cancellation, according to the Planetary Society analysis. The Veritas mission is early in development at JPL and was expected to provide work to the lab for the next several years. Veritas would be the first U.S. mission to Venus in more than 30 years and aims to map the planet's surface at high resolution and observe its atmosphere.

The budget request proposes reallocating some funding from the Perseverance rover to other planetary science missions and reducing the pace of operations for the rover. Perseverance is exploring Mars to collect rock and soil samples and search for evidence of past habitability, which researchers hope can eventually be returned to Earth for study.

Sen. Jerry Moran of Kansas, who chairs the Senate appropriations subcommittee that oversees NASA, said he would work to fund the agency similarly for 2027, saying it would be "a mistake" not to fund science missions. A spokesperson for his office said Moran plans to hold a hearing with Isaacman before the end of April to review the budget request. NASA will use the president's budget request as its roadmap until Congress passes its own budget, which could slow grants and contracts.