The Smithsonian National Air and Space Museums STEM in 30 series of live, fast-paced, 30-minute webcasts are designed to increase interest and .\rbr\rbrIn the lifetime of todays middle school students, there hasnt been a day without a human presence onboard the International Space Station (ISS). This.\rbr\rbrThe Smithsonian National Air and Space Museums STEM in 30 series of live, fast-paced, 30-minute webcasts are designed to increase interest and .\rbr\rbrSmithsonians National Air and Space Museum maintains the largest collection of historic air and space artifacts in the world. (Terms of use: .