Transcript for US astronaut blasts into the history books
Now to astronaut Peggy Whitson. She blasted her way into the history books overnight, the commander of the international space station breaking the American record for most time spent in space, 534 days. That's a long time. And president trump kt congratulated her this morning and we have former nasa astronaut Mike Massimino. Mike, 534 days -- A long time. A year and a half in a span of three missions. How big is this record, how big of an accomplishment? This is huge. I know Peggy a long time. We were astronaut classmates together 21 years ago. I think she's a great role model for all of us but particularly for women in the engineering and science field. She was the first woman to command the international space station. She did that back in 2008. She came back and became a boss, became the chief astronaut and had always been a military test pilot man who had done that job. She became the first woman to be our chief and now she has more time in space than any other American. A great accomplishment. And I love how she's so increw sieve saying it's a great moment for women but for all of us. For everybody. For everybody. You have spent a lot of time in space, maybe not quite that much. No, not that long. You know mentally and physically, what does that do? We found a couple things that are important. One is that it's important to keep connected with the Earth. So you can Skype with your family, you can call. If you have get a phone call from Houston and you don't recognize the number, take it because it might be the international space station. I got tricked a couple times. See the Houston number, pick it up because your friends can call you from the international space station. Physically you can go through a lot of changes, bone loss, muscle loss. You have to exercise. Two-hour exercise period six days a week on the international space station. Run a treadmill and also resistance exercise. You can pick up 600 pounds and not even know it in space. We have resistance exercise with springs and bands so you don't get that muscle and bone loss. Gosh. The Russian athlete who has the record, 879 days, he's retired now. Do you think Dr. Whitson has a chance to break that? She's going to get closer. If she flies again maybe she will. The Russians have a few -- smaller group of cosmonauts and they fly them over and over again. Americans have a lot of astronauts, don't get to fly as much. But records are meant to be broken even in space. You still got the fire in your eyes. I'm very happy for Peggy. Thanks for covering the story. It's a great story. Wonderful having you here.
This transcript has been automatically generated and may not be 100% accurate.