After more than 534 days in space, Peggy Whitson got a phone call. It was Donald Trump.

The president called the astronaut and commander of the International Space Station to congratulate her on breaking the record for the longest cumulative stay in space by a US astronaut. Her stay of 534 days, 2 hours, 49 minutes beat the record previously held by Jeff Williams.

A "cumulative" record accrues over multiple separate missions. Whitson's current mission is her third long-term stay on the ISS. When she returns to Earth in September she'll have extended the record to more than 650 days.

During the 23 minute call, livestreamed at NASA's YouTube page among other places, Trump was flanked by daughter Ivanka and astronaut Kate Rubins in the Oval Office. At the other end of the call, Whitson and fellow astronaut Jack Fischer floated on the ISS under a sign reading "New U.S. High Time Space Ninja."

The call focused on Whitson's accomplishments and the work of ISS astronauts, and provided an educational opportunity to schoolchildren watching nationwide. Many probably snickered at her description of one such activity.

"We're also cleaning up our urine and making it drinkable, and it's not as bad as it sounds," she said.

"Better you than me," Trump deadpanned in response.

Also discussed was a bill that targets a manned mission to Mars by the 2030s.

In another humorous aside, Trump mused that he'd like Whitson and Fischer to help figure out a faster timetable for getting to the Red Planet.

"We want to try and do it during my first term," he joked. "Or at worst during my second term."