Transcript for Trump congratulates record-breaking astronaut

White House that this mission control Houston. Please call station for a voice tech. Do you hear me. Yes there are a heavy allowed. Loud and clear. Well that's what we like great American equipment that works. And this is an easy that it. Yeah okay him it's very exciting to be here today. Very very exciting. And to speak to you live with three brave American astronaut c.s are. Our finest Caesar great great Americans great people. To join us from orbit. Aboard the International. Space Station. Commander Peggy Watson. And colonel Jack fascia. And Peggy Woodson is been setting record so we're gonna talk about that very soon. I'm here in the Oval Office along with my daughter a vodka. And pass or not Kate Rubens. Who recently returned from space. And from the space station. Together we are. Being joined by students all across America. Thousands and thousands of students. Who are learning. To learning about space learning about a lot of other things. And they're watching this conversation from the classroom. And all over. We have astronauts are we have everybody were flying right now. 171000. Miles. Per hour that's about as fast as ever and I wouldn't want to be flying. 78000 miles an hour but that's what you do. Peggy Jack and Kate I know that American students at thrilled to hear from you. But first I want to say that this is a very special day in the glorious history of American. Spaceflight. Today commander wits and you have broken the record for the most total time spent in space by an American astronaut. 534. Days and counting. That's an incredible record to break. And on behalf of our nation and frankly on behalf of the world. I'd like to congratulate you that is really. Something and I'd like to know how does it feel to broke in such a big and important record. Well XX eight a huge honor to breaker record like this but it. It's an honor for me back basically to be representing all the folks at NASA. Who make this space flight possible and you make. Mean setting its record feasible. Instead it's very exciting time to be at NASA. We are all it very much looking forward. As directed by your news and that's bill we're excited about the missions to Mars and its when he thirties. And so we're actually physically have hardware on the ground that's being built. For the SOS racket that it's going to take us there and then of course the hardware being built now is going to be for the test flights that will eventually get us there. But it's a very exciting time and I'm so proud of the team. Grated what are we learning. From having his spending your time up there I know so much research is done I'm getting a glimpse of some of it right here in the Oval Office. What are we learning by it being in space. I think probably and the International Space Station space station is providing a key. Bridge from us getting. Living honors to going somewhere into deep space so I'm those Mars missions we need to better understand. Cal micro gravity is really affecting our body and we need to understand it in great detail so many of the studies are looking at the human body. We're also looking at things that let that I am involve operations of a space vehicle on these fundraising missions. And they technological advancements that room will be required for instance on M multi year Mars mission. We're gonna need to be able to say it closed their life support system and that means. We right now for instance are taking solar powered that we collects and using it to break apart water and so oxygen and hydrogen. Oxygen we breathe a course we use the hydrogen combine it back with the CO2 that we take out of the air. And make more water. But water is sets in precious resource up here. That we also. Are cleaning up are your and and making it drinkable and it's really not as bad as it sounds. Let's go to Blair there that. Better you than me. I will say get colonel fishy you just derived and how would you trip. Complicated easy had it ago. Polisario was awesome I made it did made even my beloved of twenty to feel a little bit Ender Ballard. I just want to introduce another great one Kate group Britain's is with us today and she has been so impressive is resurgent. So many other things having to do with the mess and Kate I understand you're the first person to sequence DNA and space can you tell us about. Yet so that was actually just this last summer and it's it's a real example of what we can do with technology innovation. I was that in sequence are down to the size of yourself fun and we are actually able to fly that onboard the space station. And sequence DNA. Not just the technology demonstration but we can actually use that. To do things like detect my presence on the space station look at astronaut health. We can be easily used that an earth based settings to to look for disease outbreaks. To do for all health care as well. That's fantastic. That is really wanted to sell some of the work and it's incredibly and I've been dealing with politicians so much. I'm so much more impressed were these people you have no idea.

This transcript has been automatically generated and may not be 100% accurate.