Today, President Trump took a few moments out of his day to speak with NASA astronauts Christina Koch and Jessica Meir, who are currently conducting the first all-female spacewalk in history on the outside of the International Space Station. While speaking with the pair, Trump mistakenly suggested this was the first female spacewalk ever — a point that the astronauts corrected him on.

“This is the first time for a woman outside of the space station,” Trump said. He later added: “You are amazing people; they’re conducting the first ever female spacewalk to replace an exterior part of the space station. They’re doing some work, and they’re doing it in a very high altitude — an altitude that very few people will ever see.”

In her response, Meir made it clear that they were building on the work of many previous women who had spacewalked before them. “We don’t want to take too much credit because there have been many other female spacewalkers before,” Meir said. “This is the first time that there’s been two women outside at the same time.” In the history of spaceflight, only 15 women have ever spacewalked, including Meir and Koch.

Astronauts in space have lightly corrected the president during a phone call before. In 2017, Trump asked NASA astronaut Peggy Whitson when she thought astronauts would head to Mars, just after signing a new authorization bill for NASA that outlined the timeline for that. “Well I think as your bill directed, it’ll be approximately in the 2030s,” Whitson replied at the time.

Koch and Meir’s call with Trump only lasted about five minutes. They still have a few hours left in space after replacing a failed unit needed for charging and discharging batteries.