NASA engineers call it “death by deadline”. On July 1, agency leadership forwarded a White House order giving every threatened mission one week to outline how it would shut down forever. The memo, reviewed by Ars Technica, tells project managers to assume funding stops on October 1, the first day of fiscal year 2026. Its timing—smack in the middle of a holiday week—only sharpened the alarm.

A twenty-four-percent bite

The administration’s fiscal blueprint, released in May, slashes NASA’s top line from $24.8 billion to $18.8 billion, a cut of 24 percent. No office is hit harder than the Science Mission Directorate, which absorbs a 47 percent reduction. Out of 124 active or developing science missions, 41 would be cancelled outright and another 17 would watch their funding sink toward zero within months.

The victims span the Solar System: Juno, still orbiting Jupiter; New Horizons, now exploring the Kuiper Belt; the Psyche asteroid explorer that launched only two years ago; two long-awaited Venus probes, VERITAS and DAVINCI; and big chunks of the Mars Sample Return architecture.

OMB director Russ Vought argues that past Congresses protected too many missions in indefinite “extended operations” and that NASA must pivot to “new strategic priorities.” Agency veterans say that excuse is thin. “We would be turning off some fabulous missions that are doing extremely well”, warns Jim Green, who headed planetary science for twelve years before retiring in 2022.

The closeout commandments

The July 1 directive arrives with chilling specificity: list the date each instrument will power down, detail how you will archive remaining data, provide a staff reduction timetable, and assume the process lasts no longer than three months. For spacecraft 800 million kilometres away, three months is barely enough to draft safe-mode commands, let alone guarantee an orderly farewell. Principal investigators spent the holiday weekend on Zoom calls rather than barbecues, juggling contingency budgets and job-loss spreadsheets.

NASA’s memo claims the exercise is “planning only,” but few scientists buy it. The worry is that OMB will declare the president’s budget request the de facto operating plan if Congress fails to pass a new appropriations bill—an increasingly common outcome in polarized Washington.

Capitol Hill erupts

Reaction from lawmakers was swift and bipartisan. Senator Maria Cantwell (D-Wash.), chair of the Commerce Committee, called the cuts “a frontal assault on American leadership in space science.” Representative Brian Babin (R-Texas), whose district includes Johnson Space Center, labeled them “short-sighted and strategically unsound.” Former NASA deputy administrator Lori Garver tweeted that the plan “destroys capability we can never rebuild at today’s prices.”

Congress holds the purse, but OMB controls the cash flow between now and any final budget deal. If the agency impounds funds or issues a rescission order, months of court battles could follow.

What happens next?

Congressional staffers predict a continuing resolution this fall, but OMB reportedly plans to treat the president’s proposal as binding guidance regardless. That gambit may rely on impoundment—a maneuver last tested by Richard Nixon and partially reined in by the Impoundment Control Act of 1974. Expect lawsuits if probes start going dark without explicit congressional consent.

Behind the legal chess match ticks an orbital clock. Juno’s next perijove, Psyche’s next course-correction burn, the daily antenna schedules at Deep Space Network stations—all depend on teams that may soon receive redundancy notices. Expertise drains faster than budgets; once a project office scatters, resurrecting a mission can cost more than running it for years.

Space exploration runs on momentum. Instruments launched during one administration often deliver their best discoveries years later. So, will the lights go out at Jupiter and beyond? The answer rests on a tightrope of procedure, politics, and planetary motion.

For now, engineers keep scripting commands, scientists keep digging through data, and lawmakers huddle over spreadsheets—because in space, once a signal stops, silence is permanent.