President Donald Trump may be known for flip-flopping on issues, but he hasn’t backed away from his lofty goals in outer space. His push for a military “space force” and boots on the Red Planet has some in Congress trying to bring him back to Earth.

As senators heard Wednesday about NASA’s “search for life” in the galaxy, some Democrats wanted to talk about climate change.

Sen. Ed Markey painted a grim picture of the “deadly fires gripping California and Greece, extreme hurricanes in the Atlantic, and searing heat waves and droughts around the world” as he urged the agency to keep climate research on its scientific agenda.

“Our investments in NASA’s earth science and climate research programs must be both abundant and unwavering,” the Massachusetts Democrat said during a Commerce, Science and Transportation subcommittee hearing. 

Markey pressed the head of the agency’s Science Mission Directorate to make our own planet a priority.

“I’ll make the commitment that we will implement everything in the program that’s being appropriated here, and that includes, as you know, a strong earth science,” Associate Administrator Thomas Zurbuchen responded.

Trump’s pick to lead NASA, Jim Bridenstine, divided the Senate earlier this year. Democrats worried he would shut down certain NASA research programs and pointed to his record of downplaying human-caused climate change.

In the end, Bridenstine took the helm of the agency without Democratic support. Senators confirmed him in April on a party-line vote.

Steering Wednesday’s hearing back to NASA’s search for extraterrestrial life, Sen. Ted Cruz said exploration is an eternal human itch.

“Since the dawn of time, man has often looked up into the night the sky and wondered, ‘What’s up there?’” said the Texas Republican, who chairs the Space, Science and Competitiveness Subcommittee.

As senators considered the agency’s priorities, witnesses said changing with the times is key.

“Any institution, any kind of structure that’s been around for more than half a century, I think it should be reviewed to see if it’s still effective,” said Massachusetts Institute of Technology Professor Sara Seager, a physics and planetary science specialist.

Seager warned that if the U.S. stops investing in the search for life, other countries will lead.

“It used to be that China can copy perfectly but not innovate, and now that might be changing,” she cautioned.

NASA’s Zurbuchen had similar concerns. The strength of a country’s space exploration program can bolster its status, he said. “This is how great nations make a mark, it’s what they do for their citizens, its how they move history forward.”