Culberson has fiercely supported one mission in particular: a journey to one of Jupiter’s moons, the icy Europa.

As chair of the House Subcommittee on Commerce, Justice, and Science, Culberson more than doubled the amount of money the space agency requested from Congress for an orbiter around Europa, from $265 million to $545 million. He also threw in $195 million to support a lander to the moon, which NASA hadn’t even planned for, but would of course accept. Scientists suspect that Europa’s frozen crust covers a liquid ocean that may sustain microbial life. Culberson was intent on sending something there to find it. “This will be tremendously expensive, but worth every penny,” he said last year, during a visit to NASA’s Jet Propulsion Laboratory to check its progress.

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With Culberson out of the House, the funding portfolio for the Europa mission could change. “I don’t see any obvious members of Congress, Republican or Democratic, who’d be taking up that mantle of leading the Europa efforts, so I imagine that those are likely to start to wane,” said Casey Dreier, a senior space-policy adviser at the Planetary Society, a nonprofit space-advocacy group.

Dreier said the development of the Europa orbiter, known as Clipper, will certainly continue. Since NASA formally approved the mission in 2015, engineers and scientists have made significant progress on the design of the spacecraft. But without a steady flow of funding, its launch date could slip, he said.

The lander is on shakier ground. “I don’t think you’re going to see money for the Europa lander to continue showing up, because that’s money that NASA has not been requesting,” Dreier said.

Culberson is also a supporter of the Space Launch System, a rocket and capsule currently under construction at NASA. The launch system, intended to someday send astronauts to the moon and beyond, enjoys tremendous support in the House and the Senate, particularly from lawmakers whose states are home to NASA field centers where the work is being done. The SLS is designed to be the world’s most powerful rocket, but it has many hurdles to clear before it gets off the ground. The program has been plagued with schedule delays and cost overruns.

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“It’s just critical that we get it up and flying as quickly as possible,” Culberson told reporters in April, in an attempt to both reassure taxpayers and galvanize engineers. “Every delay is a concern and a worry.” With Culberson gone, the SLS loses a supporter to defend the program from criticism, both in Congress and the broader space community, that it is too costly.

Culberson is likely to be replaced as chair by José Serrano of New York, the current ranking member of the committee. Asked on Wednesday whether he would continue Culberson’s efforts to keep the Europa mission well funded, the congressman said, “My priority right now is getting a final fiscal year 2019 [appropriations bill] that achieves good outcomes on an array of important priorities both inside and outside NASA.”