US President Donald Trump today made a very, very long distance call, from his Oval Office to the International Space Station, to congratulate Peggy Whitson who broke the record for most days in space by a US astronaut. He spoke with Whitson, commander of the International Space Station, and fellow astronaut Jack Fischer. When Trump asked Whitson "what we are learning from space", she explained to him some of the challenges of living on the ISS. She informed him of an experiment aboard the space station to convert urine to water - which the astronauts have drunk, saying "it's really not as bad as it sounds". "Water is such a precious resource up here that we also are cleaning up our urine and making it drinkable. And it's really not as bad as it sounds," she said. Trump quipped, "Well, that's good. I'm glad to hear that. Better you than me." Fischer gave his own perspective to the challenges of living at the space station. "It's amazing. Oh, and then, you know, now I'm talking to the President of the United States while hanging from a wall. It's amazing," he said. The International Space Station is, by far, the best example of international cooperation and what we can do when we work together in the history of humanity. "I am so proud to be a part of it. It's just cool," he said. Whitson said on a typical day the astronauts wake up and look at the messages from the ground. On any given day, it can be dramatically different, she added. Also Watch: On one day, we might be focusing on science. On another day, we might be repairing the carbon dioxide removal system. On another day, soon Jack and I are going to do a spacewalk. We talked about, last Saturday, we did robotics operations. I love the diversity of the different activities that we do. Plus, you know, we have over 200 investigations ongoing on board the space station, and I just think that\u2019s a phenomenal part of the day," Whitson said. Trump said the astronauts are making great difference to the mankind. "You're making a great difference, I have to say." Fischer said this is probably the most exciting in space exploration, certainly in his lifetime. "We are about to just have an explosion of activity. There is so much involvement on the space station with commercial industries and commercial partners. We have an entire program to manage the science," he said.