More than 100 retired NASA astronauts have launched a voting campaign focused on young voters, warning that they believe American democracy is under threat and urging participation in the November election.

The group, called Astronauts for America, began its “Vote for Freedom” campaign on July 20, the anniversary of the Apollo 11 moon landing. Its message centers on the view that the country is facing a direct challenge to democratic institutions and that voters, particularly younger Americans, should turn out at the polls.

Charles Bolden, who served as NASA administrator under President Barack Obama and flew four space shuttle missions, linked the effort to what he described as President Donald Trump’s “assault on democratic norms.”

“We may not make it if we don’t do something now,” Bolden said. He also warned that the country may be running out of time to respond politically. “We may not have another presidential term to try to make a difference,” he said.

The astronauts have framed their campaign around the perspective gained from seeing the United States and Earth from orbit. Astronaut Cady Coleman, who spent six months aboard the International Space Station, said that experience removed the political and geographic divisions commonly emphasized on the ground.

“During my spaceflights, I literally didn’t know and never asked about their politics,” Coleman said. “But now we’re all together, and what we’re fighting for is something that’s common to all of us—we’re fighting for our country, for our democracy.”

The campaign plans to visit about 60 college campuses in swing states, with the goal of encouraging young people to vote. Those states can carry outsized importance in presidential elections because the Electoral College, rather than the national popular vote, determines the winner.

Organizers are not presenting the effort as aligned with either the Democratic Party or the Republican Party, but as a civic campaign centered on voting and democratic participation.

Linda Godwin, another veteran astronaut, described the group’s view of the effort in mission-oriented terms. “Right now, we think our country is the mission,” she said.

The group also plans to grade congressional candidates on their commitment to the Constitution, according to the campaign’s stated plans.

Ellen Ochoa, the first Latina in space, emphasized voting as a basic requirement of democratic government. “A democracy depends on people actually participating. Voting is the single most important thing you can do,” she said.

The astronauts have summarized the campaign with a phrase that echoes Neil Armstrong’s Apollo 11 statement: “Going to the polls is one small step for you, and one giant leap for our country.”

With 100 days until the election, the group is presenting its campaign as an urgent appeal for civic participation and the defense of democratic norms.