One vote in the 2020 U.S. presidential election wasn’t cast from a voting booth or by mail, but from 250 miles up aboard the International Space Station.

The big picture: NASA astronaut Kate Rubins is far from the first person to exercise her civic duty from orbit. Cosmonauts and astronauts have voted from space for decades.

• "I think it's really important for everybody to vote, and if we can do it from space, then I believe folks can do it from the ground, too," Rubins told the AP last month.

How it works: Astronauts in space can vote by receiving an encrypted ballot from mission control. They then fill out the ballot and send it back to Earth, where it's sent to a registrar who converts the electronic ballot and counts the vote.

• That process is possible because Texas passed a law making it legal for residents of the state to vote from orbit.
• No other states have this law on the books, but all active NASA astronauts need to live near Houston, so the Texas law is effectively a catch-all for Americans heading to space right now.

Background: The first people to vote from space were Russian cosmonauts aboard the space station Mir, according to space historian Robert Pearlman.

• "Yury Usachov and Yuri Onufrienko were aboard Mir with American astronaut Shannon Lucid. In June of 1996, the two of them voted in the Russian presidential election that year," said Pearlman, who runs the website Collectspace.com.
• NASA astronaut David Wolf then voted in a local election from Mir in 1997.
• And NASA's Leroy Chiao became the first American to cast a vote for president from orbit aboard the ISS in 2004.

What's next: Eventually, space voting laws might have to be adopted elsewhere in the U.S., if private astronauts are going to be living and working in space for the long haul.