Another mission the White House wanted to cancel was THEMIS, a pair of spacecraft orbiting the moon to map the lunar magnetic field. The mission's lead scientist, Vassilis Angelopoulos of UCLA, said his team will receive “partial funding” for fiscal year 2026.
“This is good, but at the same time it means that the scientific staff are deprived of funding,” Angelopoulos told Ars. “As a result, the United States is not getting the scientific returns it could get from its multibillion-dollar technology investments.”
An artist's concept of NASA's MAVEN spacecraft, which has been orbiting Mars since 2014 and studying the planet's upper atmosphere.
To summarize: The missions already in space that the Trump administration wants to cancel represent a combined investment of $12 billion, according to the Planetary Society, a science advocacy group. Ars rating concluded that the operational missions scheduled for cancellation would cost taxpayers less than $300 million per year, or 1 to 2 percent of NASA's annual budget.
Supporters of NASA's science program met at the US Capitol this week to highlight the threat. Angelopoulos said protests from scientists and the public appear to be working.
“I view the House budget performance as an indication that voter pressure is working,” he said. “Unfortunately, the damage has already been done. Even if funding is restored, we have already lost people.”
Some scientists are concerned that the Trump administration could try to withhold funding for certain programs even if Congress provides a budget for them. This will most likely provoke a fight in court.
Bruce Jakoski, former principal investigator of the MAVEN Mars mission, expressed these concerns. He said it is a “positive step” that NASA is now making plans, based on the assumption that the agency will receive the budget laid out by the House of Representatives. But there's one catch.
“Even if the budget passed by Congress is signed into law, the President will show no reluctance not to spend money that was obligated by law,” Jakoski wrote in an email to Ars. “This means that having a budget is not the end; and the distribution of money to the MAVEN science and operations team is not the end: only when the money is actually spent can we be sure that it will not be returned.
“This means uncertainty is with us throughout the financial year,” he said. “This uncertainty is bound to lead to morale problems.”
