“From the International Space Station: I voted today,” said Ms Rubins in a tweet shared by NASA.
From the International Space Station: I voted today
— Kate Rubins pic.twitter.com/DRdjwSzXwy
— NASA Astronauts (@NASA_Astronauts) October 22, 2020
The space agency explained that a secure electronic ballot was uplinked to the space station by mission control at the Johnson Space Center in Houston, Texas.
Ms Rubin was then sent an email with her credentials on it from the clerk of Harris County, Texas, which gave her access to the ballot.
Ms Rubin was then able to cast her vote and the ballot was downloaded to the county clerk to be officially recorded.
“I think it’s really important for everybody to vote,” said Ms Rubins, who is on a six-month stay onboard the ISS.
“If we can do it from space, then I believe folks can do it from the ground, too.
“It’s critical to participate in our democracy.
“We consider it an honour to be able to vote from space.”
It is not Ms Rubin’s first time voting in space as she did the same from the ISS for the 2016 election.
Astronauts have been able to vote in space since 1997 when a law was passed in Texas to allow it.
NASA says it plans to continue the practice on its planned missions to the moon in 2024 and eventually from Mars.