WFIRST just passed a big design review at NASA headquarters this month. The mission has also trimmed its budget after an independent review found the telescope was getting too expensive. Now, however, its future is less certain. WFIRST scientists and engineers must now wait for Congress to negotiate its own budget proposals for fiscal year 2019 in the coming months, and hope the telescope fares better with lawmakers than it did with the president. If past negotiations are an indication, it likely will.

“It’s terrible,” says David Spergel, a Princeton University astrophysicist and cochair of the WFIRST science team, of the Trump administration’s recommendation to cut the mission. “We’re sort of abandoning leadership in space astronomy.”

NASA broke ground on WFIRST development in 2016. The mission was gifted a 2.4 meter telescope from the National Reconnaissance Office, an agency within the U.S. Department of Defense. The telescope would feed the mission’s main instrument, an imager designed to investigate dark energy, the mysterious substance astrophysicists believe makes up most of the universe. Another instrument, a coronagraph, would directly image and study the chemical compositions of exoplanets outside our solar system.

Then last year, WFIRST got some bad news. A committee NASA established to look into the costs of the mission found that WFIRST is “not executable” without more funding, according to a report publicly released last November. NASA headquarters told the WFIRST team to find a few hundred million dollars in the mission’s budget and cut it. “It’s not fun for anybody,” said Jeffrey Kruk, the project scientist for WFIRST, last year, as his team prepared to look for places to shave off costs. “It’s very stressful. We’re trying to come up with the right answer, the best answer we can.”

The WFIRST mission met the recommended target of $3.2 billion this month. According to Trump’s budget request, that’s still too much. The administration has proposed $19.9 billion for NASA for fiscal year 2019, slightly more than its request for fiscal year 2018—which is still being worked out, following two government shutdowns and many late nights on Capitol Hill. The latest proposal shows the funding WFIRST received for fiscal year 2017, which was $105 million. In the column showing Trump’s request sits a big, fat zero.

Kruk said Monday the team is hopeful that the final budget “will be more favorable.” For the fiscal year 2017 budget, the Obama administration requested $76 million for WFIRST development. Congress called for more, and the final budget approved $105 million.

WFIRST emerged from a 2010 decadal survey by the National Research Council, which outlines priorities in astronomy and astrophysics for the United States. The nation’s biggest and most productive space telescopes all trace their origins back to such decadal surveys, including Hubble, the Spitzer Space Telescope, the Chandra X-Ray Observatory, and the Fermi Gamma-Ray Space Telescope. “There has been a long tradition of support by the Congress, the administration, NASA, and the [National Science Foundation] to respect the priorities of past decadal surveys,” says Alan Boss, an astronomer at the Carnegie Institution for Science and one of the many members of the committee that first brought WFIRST to life. “It would set a devastating precedent for future decadal surveys if this FY 2019 proposal is to stand.” Scientists are already starting preparations for the next decadal survey, and Trump’s proposal, Boss said, “would throw that deliberative process into absolute confusion.”