Astronauts Suni Williams, left, and Butch Wilmore give a news conference aboard the International Space Station on July 10. NASA via AP

Mail-in and absentee voting is in full swing, with the U.S. presidential election less than a week away. Some of those ballots have further to travel, especially in vertical distance, than others.

Some 250 miles above Earth, the four American astronauts aboard the International Space Station – orbiting the planet at 17,500 mph – said they intended to cast their votes from the thermosphere, according to NASA public affairs officer Jimi Russell.

That includes Suni Williams and Butch Wilmore, who are stuck in space after their eight-day mission to the ISS was extended to eight months after a technical malfunction in the Boeing Starliner that was supposed to bring them home. In a news conference last month, Wilmore said he had requested his ballot. He did not say for whom he would vote.

“It’s a very important role we play as citizens to be included in those elections,” Wilmore said.

Americans living or traveling abroad can fill out a mail-in form, so long as they are registered in a former state of residence. But for Americans in space, there’s more to it than sealing and stamping an envelope. Absentee or early-voting ballots on the ISS are downloaded with a special password, filled out, and uploaded and encrypted on board. NASA satellites then beam them down to a ground terminal in White Sands, New Mexico, where they are then transferred to mission control in Houston. From there, the ballots are sent to county clerks for filing.

NASA declined to disclose to The Washington Post each astronaut’s registered county of residence.

In past elections, space votes have been cast in hotly contested states. U.S. astronaut Andrew R. Morgan told The Post in 2020 that he made a point to request his ballot from Lawrence County, Pennsylvania, to vote in the election.

“To be perfectly honest, outside of presidential years, I don’t always make the effort to vote,” Morgan said at the time. “But I wanted to exercise that right from the International Space Station.”

Since 1997, U.S. astronauts have had a clear process by which to cast their votes from space, after John Blaha raised the issue with NASA ahead of the 1996 presidential election, during which he was set to be aboard the Russian space station Mir.

One year later, the opportunity to “vote while you float” was enshrined – a sometimes year-long process that begins on Earth before launch and culminates in the submission of an encrypted electronic ballot from space. Morgan said Lawrence County emailed him a ballot he could fill out using a special passcode known only to him.

Other countries have followed suit.

Russian cosmonaut Anatoly Ivanishin cast his vote from orbit in 2020. Using an online ballot, Ivanishin weighed in on President Vladimir Putin’s proposed constitutional changes, aimed at keeping him in power until 2036. Ivan Vagner, another Russian in orbit, cast his vote on the matter days later through a proxy – a voter deputized to represent him back on Earth.

The European Space Agency’s Thomas Pesquet, during his tour on the International Space Station, also used a proxy to cast his vote for the next leader of France in 2017. Though a resident of Frankfurt, Germany, at the time, the French citizen was able to have a colleague vote on his behalf.

Former president Donald Trump has said he lost reelection in 2020 because of fraud surrounding increased mail-in voting due to the coronavirus pandemic. This year he and other Republicans have changed their tune, urging supporters to vote early.

“We can’t afford to wait,” Wisconsin GOP Chairman Brian Schimming said during a news conference this month. “We encourage people to vote early because you never know what’s going on with the weather.”