To the long list of ambitious goals he has set, no matter how far-fetched they might seem, President Trump on Monday added this: placing humans on Mars.

In a dramatic call from the White House with a pair of astronauts at the International Space Station, Trump urged NASA to speed up its exploration timeline to get humans on Mars “at worst, during my second term.”

Trump was celebrating Commander Peggy Whitson, an astronaut who set a new U.S. record of cumulative days in space at more than 534 days. Trump spoke live on a video conference call for about 20 minutes from the Oval Office with Whitson and a second astronaut, Flight Engineer Jack Fischer, who also was at the space station. The president marveled at the sophisticated technology that allowed them to have a relatively clear conversation.

“That’s what we like, great American equipment that works,” said Trump, who sat at his desk and was flanked by his daughter, Ivanka, and astronaut Kate Rubins. A number of advisers, including Education Secretary Betsy DeVos, also were in the Oval Office during the call.