The budget cuts NASA's $7.33 billion science budget nearly in half, affecting multiple missions. Photo / Getty Images
There is a fully tenured Nasa spacecraft named Mars Odyssey that has been faithfully orbiting the Red Planet since October 2001.
It has made more than 100,000 spins around Mars. No spacecraft has orbited a distant planet for so long.
Odyssey has a few old-age issues, including running low on the fuel for thrusters that help it point in the right direction.
But it works, beaming data about Mars and images of the surface back to Earth. As a side hustle, it has served as a communication relay for Nasa’s Mars rovers.
What it can’t do is control the budgetary process in Washington.
Mars Odyssey is one of many Nasa science missions targeted for termination or major cuts in United States President Donald Trump’s financial year 2026 budget request to Congress.
Trump’s budget would cut Nasa’s US$7.33 billion ($12.2b) science budget nearly in half. The Administration’s argument is simple: Nasa has too many science missions.
“While Nasa’s science missions have greatly expanded humanity’s understanding of the Earth, solar system, and universe, the current expenditure of over US$7b per year on over 100 missions is unsustainable,” the president’s budget request said.
It added that the Administration’s US$3.9b request will support “a leaner, more focused science programme that reflects the Administration’s commitment to fiscal responsibility”.
Already the agency is seeing a brain drain. Nasa officials have said they need to downsize the agency now even before congressional decisions on the 2026 budget.
“Based on what was proposed and based on the Administration’s priorities, we must take steps now to start realigning our workforce and the resources to meet the mission needs,” deputy associate administrator Casey Swails said in a Nasa town hall.
The agency has offered buyouts and incentives to retire early.
About 900 people – 5% of the workforce – left in February in the first wave of departures, and another 1500 signed up by late June for a voluntary separation programme that extends to July 25, a Nasa spokesperson said.
The space science community is fighting back. Dozens of contractors and agency staffers staged a protest outside Nasa headquarters on June 30, waving handmade signs saying: “Save Nasa”.
On Tuesday, seven former Nasa associate administrators of the science mission directorate – every living alumnus of the job overseeing the agency’s broad science portfolio – released a letter they had sent to congressional appropriators decrying the Trump cuts to science.
The former Nasa officials extolled the importance of space science for spurring innovation, attracting talent from across the globe, boosting America’s stature and spinning off valuable technology.
And they cited the competition with China for dominance in solar system exploration.
“[I]f the Administration is committed to countering the growing Chinese capability in space, the US needs to continue its investment in US space science, not cede it unilaterally.
“Global space competition extends far past moon and Mars exploration. The Chinese space science programme is aggressive, ambitious, and well-funded,” the former officials said.
John Grunsfeld, who led Nasa science during President Barack Obama’s second term and was among the signatories, said the scientific achievements of the agency, such as the discoveries by the Hubble and Webb space telescopes, are hugely popular with the general public.
Both telescopes will continue to be funded under Trump’s proposal, with some cuts, but Nasa’s astrophysics division would be devastated, losing two-thirds of its budget.
“We’re basically removing the wonder and awe from our portfolio,” Grunsfeld, an astronomer and five-time space shuttle astronaut who made three trips to the Hubble telescope in orbit, told the Washington Post.
Trump wants to zero out Nasa’s STEM engagement. The budget document states that the agency’s primary role is space exploration and “will inspire the next generation of explorers through exciting, ambitious space missions”.
The winner in the Trump budget, as well as in the massive tax and immigration legislation dubbed by Trump the One Big Beautiful Bill and signed into law last week, is human spaceflight. The moon comes first.
Nasa’s Artemis programme, started during Trump’s first term, seeks to put boots on the moon in just two years – outracing the Chinese, who have their own plans for the moon. Technical challenges make the official timeline extremely unlikely.
The current Artemis architecture calls for SpaceX’s Starship to serve as the lunar lander, but it has experienced launch failures. It has yet to fly with astronauts aboard.
Under its contract with Nasa, SpaceX is required to demonstrate that Starship can be refuelled in orbit, a feat never yet achieved.
And the Starship Human Landing System must also land safely on the moon in an uncrewed flight before the agency will give the go-ahead for a landing with astronauts.
Blue Origin, Jeff Bezos’ commercial space company, also has a Nasa contract to develop a lunar lander.
The uncertainties for Nasa reach the top level of the agency: there is no permanent administrator.
Jared Isaacman, an entrepreneur who has flown to space twice via SpaceX’s Falcon 9 rocket, had his nomination pulled by Trump.
Nasa’s future will be determined to a large degree by congressional appropriators.
The proposed cuts to the science missions are particularly devastating to two Nasa centres located in “blue” states: the Jet Propulsion Laboratory in Pasadena, California, and the Goddard Space Flight Centre in Greenbelt, Maryland.
JPL, managed by the California Institute of Technology under contract with Nasa, has received more than US$2.2b annually in Nasa funding in recent years but would get only US$890 million if the Trump budget were passed as written. Goddard, home to 7000 scientists and engineers, could lose close to half its workforce.
The agency on the whole would have the smallest science budget since 1984, according to an analysis by the Planetary Society, a space science advocacy organisation.
Odyssey is not the only robotic probe in Trump’s crosshairs. The Mars Atmosphere and Volatile Evolution (Maven) orbiter, launched in 2013, is also marked for cancellation, as is Juno, orbiting Jupiter since 2016.
“I was devastated,” Philip Christensen, an Arizona State University geophysicist who is part of Odyssey’s science team, said of the proposal to kill these older Nasa missions.
Nasa credits Odyssey with a major discovery, the detection of abundant frozen water beneath the Martian poles.
It mapped the surface textures, monitored the atmosphere and identified minerals in the soil.
With other robotic orbiters and rovers, it has helped demystify Mars, turning it into the planet humans know better than any other except their own.
If humans attempt to land and survive on Mars, the knowledge from robotic exploration will be key for their survival, including their ability to manufacture their own fuel from natural resources.
According to Nasa, Odyssey cost US$218m to build and then launch in 2001. In the 2025 budget it enjoys an outlay of US$10m – about 1/22nd of the cost of getting it to space in the first place.
This is true of other older missions as well. The Hubble Space Telescope in 2025 will cost taxpayers about US$93m to operate.
Launching new telescopes cost many multiples of that. The Webb launched in 2021 with the dubious distinction of costing $10b – it was dubbed “the telescope that ate astronomy” – but it has been a spectacularly successful instrument.
It received $187m in the 2025 budget, which Trump’s proposal would cut to $140m.
In theory, money saved through trimming existing missions like Hubble and Webb and outright cancelling older missions like Odyssey and Juno could go to new missions.
Those new “starts,” in Nasa-speak, might employ more advanced technologies and create new opportunities for a younger generation of scientists and engineers.
But new starts are strikingly few. Even before Trump’s second term, Nasa scientists were dealing with a dwindling number of new science initiatives. Trump would cancel many of those future proposals in addition to terminating many older missions.
Maven’s principal investigator, Shannon Curry, a planetary physicist at the University of Colorado, said killing the science missions makes no sense from either a scientific or budgetary perspective.
A spacecraft like Maven is yielding information about Mars that would be useful for a future human mission there, and the cost of operation is less than what it would take to replace it, she said.
“I truly don’t understand the logic of how that could actually save money and further American pre-eminence in space,” she said. “It would be the first step to destroy it.”
Scientists and project managers for the science missions have a disadvantage. Many of the missions are hard to explain in an lift pitch.
Richard Zurek, who had been the lead scientist for another Mars mission, Mars Reconnaissance Orbiter, retired a few weeks ago from Nasa’s Jet Propulsion Laboratory.
That mission is not terminated in the Trump budget and faces only a modest cut. But Zurek, like many people at Nasa, is concerned that the agency is running low on science missions and easing away from robotic exploration.
“We’ve had a golden age of space exploration,” Zurek said. “I hope we don’t lose what has been a terrific enterprise for humanity.”
In the community of old spacecraft, the two Voyagers are superstars. Launched in 1977, they are now in interstellar space, beaming back data with a dwindling array of instruments as they run low on power. They are likely to go silent in less than a decade.
A mission can also end accidentally. The two Viking landers, which famously searched for life on Mars in 1976, continued to transmit to Earth for several years despite dwindling power.
However, Zurek said, a new person on the Viking team inadvertently overwrote a piece of computer code that was necessary for keeping one of the landers pointed towards Earth.
“This is the way missions can die. You cut the budgets. Mistakes are made,” he said.
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