Space Exploration Milestones and Timekeeping in Space

For the first time, a NASA spacecraft is flying through the Sun's atmosphere. Nour Raouafi, project scientist for Parker Solar Probe, explains why the Sun's corona is the source of one of the biggest mysteries in all of space science. So, what does it take to build a probe that can touch the Sun—including surviving temperatures of 2,500 degrees Fahrenheit and barreling through sudden eruptions of solar plasma—and live to tell the tale? We'll also go inside the fleet of NASA spacecraft studying the Sun from many angles, including the rescue mission to save a wildly spinning observatory before it became lost in space forever.