Trump administration moves to tighten the noose around NASA science missions

"We would be turning off some fabulous missions that are doing extremely well."

In another sign that the Trump White House is aggressively moving to slash NASA’s science programs, dozens of mission leaders have been asked to prepare "closeout" plans by the end of next week.

The new directive came from NASA's senior leadership on Monday, which is acting on behalf of the White House Office of Management and Budget. Copies of these memos, which appear to vary a little by department, were reviewed by Ars. The detailed closeout plans called for must be prepared by as soon as July 9 for some missions, which has left principal investigators scrambling due to the tight deadline and the July 4 holiday weekend.

Projects should prepare their plans assuming closeout direction is given on October 1, 2025, one of the NASA memos states. Missions in operations—that is to say, spacecraft whizzing around the Solar System conducting science right now—should "assume closeout is complete within 3 months."

The memos are careful to state that the preparation of these closeout plans is for the purposes of a "planning exercise only." However, multiple scientists familiar with the new directive from NASA's leadership do not believe these closeout plans are merely for planning purposes.

Instead, based on the budget process to date and statements from the White House, they view the memos as an effort by the Trump administration to move forward with canceling as many NASA science missions as possible before Congress passes a budget for the upcoming fiscal year, 2026. This fiscal year begins on October 1, three months from today.

Science at risk

The Trump White House released its proposed budget for NASA a little more than a month ago, seeking to reduce NASA's budget by about 24 percent, from $24.8 billion this year to $18.8 billion in fiscal year 2026. Some areas within the budget were hit harder than others, particularly the Science Mission Directorate, which sustained nearly 50 percent in proposed cuts.

The space agency has 124 science missions in development, prime operations, or extended operations. Effectively, the proposed cuts would cancel 41 of these missions, and another 17 would see their funding zeroed out in the near future. Nearly half of NASA's science missions would therefore end, and dozens more would receive budget cuts of 20–40 percent.

This includes some high-profile casualties, including NASA's only mission at Jupiter, an effort to explore an asteroid that will fly extremely close to Earth in 2029, two promising missions to Venus, and an effort to return samples from Mars.

"We would be turning off some fabulous missions that are doing extremely well," said Jim Green, a physicist who led NASA's Planetary Science Program for 12 years before his retirement in 2022.

Normally, after the White House proposes a budget for the upcoming fiscal year, it is considered by appropriators in Congress responsible for setting funding levels and publishing a budget. However, in recent years, Congress has been unable to agree upon a budget and pass it before the beginning of the next fiscal year. This has led to a "continuing resolution" in which, generally, NASA missions continue to receive funding consistent with budget levels set during the previous fiscal year.

However, multiple sources indicated to Ars that may not happen this year, and the new memos offer an important clue in this regard.

Making missions go dark

The memos were sent to the principal investigators of the missions that the White House budget seeks to cancel. On one hand, it is prudent to have a plan of action in place should these missions actually be canceled due to a new budget, assuming one is in place by October 1. It is NASA's job to execute the budget it is given.

But there very likely is a more cynical plan at play here. The Office of Management and Budget, led by Russ Vought, has been seeking to cut the US government's science portfolio across the board, and it fully expects a continuing resolution to be adopted as Congress almost certainly won't have a budget signed.

The congressional committees have been paralyzed, to some degree, by the Trump administration's full-court press to pass the "One Big Beautiful Bill," which exists outside of the traditional budget process. Congressional work to set the budget for fiscal year 2026 remains in its early stages, and with summer recesses looming, passage of any bill will almost certainly require many months.

Amid this uncertainty, Vought appears to be moving to shut down as many of these missions as possible.

The PBR is the plan

How will Vought and his office accomplish this? Effectively, they seek to turn the president's budget request into the operating plan for NASA—instead of a continuing resolution—in the absence of a fiscal year 2026 budget.

This has already been communicated to NASA's field center directors. Recently, according to multiple sources, NASA's chief of staff, Brian Hughes, told these center leaders that the president's budget request would soon become their operating plans. Hughes, who worked on Trump's 2024 campaign, is one of the senior political leaders running NASA in the absence of a confirmed administrator.

During a typical budget year, NASA officials submit an operating plan to Congress so authorizers and appropriators know what is happening at the agency as part of the budget-making process. During this give-and-take, appropriators provide feedback; i.e., "continue working on such and such" because it is the intent of Congress to continue funding that activity regardless of the White House's proposed budget. For example, this process saved NASA's Chandra X-ray Observatory from having its operations rapidly curtailed last year.

NASA typically complies with guidance from Congress since it receives its budget from Congress. (Really, you do not want to bite the hand that feeds.) However, this year's process is not expected to be normal, and there is no legal requirement for NASA (or other federal agencies) to consider congressional feedback on their operating plans.

This year, in fact, the Office of Management and Budget has even stopped NASA from submitting operational plans to Congress.

"This is yet another bad faith move by the administration, which seems hell-bent on attacking science and the future of American innovation," said Rep. George Whitesides (D-Calif.), who previously served as NASA's chief of staff. "To go around Congress, and the committee of jurisdiction that I sit on, to enact their radical agenda that will make us less safe, less competitive, and less able to respond to threats is not only dangerous, it will cede all ground to our adversaries like China."

Will the last planetary scientist please turn out the lights?

How will this play out?

There are multiple strategies, and some of them are likely to end up in court fights. Philosophically, Vought believes strongly that the president should have more authority to direct federal spending. And he appears likely to try to force the issue this year. Using tactics such as recission—essentially ordering federal agencies to freeze spending—and impoundment, Vought will seek to implement the priorities in the president's budget request, which his office wrote.

Beginning October 1, without a fiscal year 2026 budget in place, NASA may be directed to start following the closeout plans submitted this month by principal investigators and turning missions off. That means the lights go out at Jupiter, telescopes stop gathering data across the Solar System, and so on for dozens of missions.

And once those missions are gone, they're almost impossible to bring back—even if Congress were inclined to restore funding months later with a new budget.

"If there’s not much hope to restart a mission, the people who are managing Juno, New Horizons, and other missions are going to be looking for their next job," Green said. "They’re going to be gone. Within a few months, you won’t be able to get the expertise back. And without the expertise, you don’t have the ability to run the mission safely."