President Donald Trump’s fiscal 2026 budget request, if approved by Congress, poses a significant threat to many of NASA’s ambitious plans for robotic exploration of the solar system. The proposed cuts would not only eliminate a variety of space-based missions aimed at studying Earth, the sun, and the broader universe but also significantly reduce attention given to key planets like Venus, Mars, and Jupiter. Notably, the planet facing the most substantial decrease in scientific scrutiny would be our own, with the budget proposal suggesting a staggering 53 percent reduction in funding for Earth science.
Among the most iconic NASA missions, the twin spacecraft known as the Voyagers were launched in 1977 and are celebrated for their breathtaking images of the outer solar system. Currently, Voyager 1 is over 15 billion miles from Earth, while Voyager 2 is more than 13 billion miles away, placing them beyond the heliopause, the boundary where the solar wind from the sun ceases. The proposed budget aims to cut funding for the Voyager missions from $7.8 million to $5 million in 2026, with further reductions leading to zero funding by 2029.
Although a reduction in funding was somewhat expected due to the diminishing power of the Voyager spacecraft—operating on the radioactive decay of plutonium-238—it is important to note that these missions continue to yield invaluable data on particles and radiation in interstellar space. This research is unique and cannot be replicated by telescopes or computer models alone.
It’s crucial to remember that the proposed cuts to NASA’s space science missions are not final. Lawmakers may advocate for the preservation of programs that are significant to their states and districts. The Senate Commerce Committee is currently working to safeguard NASA’s budget, which the White House has suggested cutting by nearly one-fourth. Most of the funding supported by the Senate is expected to focus on human spaceflight rather than scientific research.
For instance, the committee aims to extend the operational lifespan of NASA’s heavy-lift Space Launch System (SLS) rocket, which the Trump administration had proposed to cancel following the Artemis 3 lunar landing scheduled for 2027. Additionally, the Senate's budget proposal would secure funding for the Gateway, a space station intended to orbit the moon. Sources familiar with these efforts suggest that there is little expectation of pushback from the White House, especially after Trump’s unexpected fallout with Elon Musk.
Interestingly, the Trump budget proposal includes plans for a billion dollars in new funding dedicated to human exploration of Mars. This allocation would support initiatives to “test capabilities for a near-term human-class Mars lander” and develop specialized spacesuits for Martian conditions. However, this investment falls short of the sweeping strategic shift from lunar to Martian exploration that seemed feasible last fall, especially given Musk and Trump’s mutual interest in a Mars mission within a few years.
Nonetheless, any mission to Mars would encounter significant technical and budgetary challenges. Historically, NASA has struggled to land payloads on Mars that exceed the weight of a small car. The Martian atmosphere, with only about 1 percent of Earth’s atmospheric density, presents additional complications, as it is too thin to effectively slow down incoming vehicles, yet dense enough to pose challenges during descent.
In summary, President Trump's fiscal 2026 budget proposal represents a potential turning point for NASA's exploration initiatives. With significant cuts to Earth science funding and the Voyager missions, alongside a mixed bag of support for Mars exploration, the future of NASA's scientific endeavors hangs in the balance as Congress debates the proposed budget.
