Transcript for NASA and SPACE-X face critical decisions as 2 astronauts plan return
Now to the critical decisions for nasa and spacex as astronauts plan to leave the international space station. And splash down off the coast of Florida. Once their capsule undocks from the space station, they have just 48 hours of oxygen so make it home. Is Isaias throwing this plan off course? Here's gio Benitez with the latest. Reporter: Tonight the countdown is on. Will the dragon endeavor undock from the international space station to begin its long journey home? With tropical storm Isaias off the coast of Florida, the astronauts are set to attempt a rare splashdown in the gulf. Something that hasn't been done in 45 years, putting their faith in the forecasters. Are you at all concerned that this storm may be too close for comfort? Every six hours we'll get another forecast, sort of an update, so we're watching those closely. Reporter: Bob Behnken and Doug hurley made history two months ago, launching from U.S. Soil for the first time aboard a commercial spaceship. When they undock, they'll orbit the Earth at more than 17,000 miles per hour. They'll have just 48 hours' worth of oxygen on board, so they must get to Earth. That splashdown expected Sunday afternoon, if the weather behaves. The teams are working really hard, especially with the dynamics of the weather over the next few days around Florida, and we appreciate those efforts, because I know those those decisions and that work isn't easy. Reporter: The two men finally bringing home that now-famous glitter dinosaur, chosen by their sons. For jack and Leo, trimmer the apatasaurus is headed home soon, and he'll be with your dads. You'll have to pick which one of us is your favorite. Gio Benitez joins us now live from the Johnson space Senter in Houston. Gio, so much on the line right now. They're in the capsule, waiting for the final go-ahead? Reporter: Yeah, that's right, Tom. Once they undock, there is no
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