 Reach for it, presented by Science at NASA. In August 1984, President Ronald Reagan announced NASA's plan to send one of America's finest a teacher to space aboard Space Shuttle Challenger. Of 11,000 aspirants for the adventure, 37-year-old high school teacher Christa McAuliffe from Concord, New Hampshire was chosen. As the first teacher traveling to space, she planned to conduct science demonstrations from low-Earth orbit to get students, quote, excited about history, about the future, and about space, end quote. Tragically, Challenger broke apart soon after liftoff on January 28, 1986. There were no survivors, and McAuliffe's planned demonstrations were shelved. International Space Station astronauts Joe Acaba and Ricky Arnold have brought McAuliffe's mission full circle by completing and filming on orbit her envisioned lessons as a tribute to her legacy. U.S. crew members aboard the station have also performed and captured other brief, engaging lessons or STEM demonstrations. As part of the year of education on station, NASA has made all of the demos available to classrooms around the world. Chromatography is one of the most interesting McAuliffe lessons Acaba and Arnold have brought to life. It provides hands-on activities for students to understand the importance of capillary action and chromatography and compare how they work in microgravity versus on Earth. Capillary action occurs any time a liquid spontaneously flows into a narrow tube or porous material. It's how plants get water from their roots to their leaves. It's how our blood makes a round trip through our bodies. And it's how those paper towels soaked up the orange juice you spilled this morning. Chromatography is a technique that uses capillary action to separate mixtures so they can be analyzed. On Earth, chromatography is used for activities such as studying samples at a crime scene. Chromatography is an essential technique for spaceflight, too. For instance, keeping crew persons safe from contaminants includes analyzing unknowns, which can be critical on long space missions. An example of a Year of Education STEM demonstration features NASA astronaut Randy Bresnick slingshotting objects of all sizes across the inside of the space station with a bungee cord. He's illustrating how Newton's second law of motion holds true in microgravity just like on Earth. Simply put, Newton's law states that the greater the mass of an object, the more force it will take to accelerate it. Year of Education on Station also included more than 60 opportunities for hundreds of students and teachers to connect via in-flight education downlinks with astronauts aboard the space station for live question and answer sessions. Participants ask questions about all aspects of living and working in space. Hi, my name is Ramsey, and my question is, have you ever had the idea to get a lot of water, pour it out, and see what happens? See how it just sticks to my hand? It just waves there. It doesn't really go anywhere. It just sticks right to the surface so I could drink my lemonade right from my hand. How do you grow plants in microgravity without soil and water getting everywhere? One of the plants actually uses pillows that are impregnated with moisture and the nutrients they need. We have another advanced plant habitat that I've been working on where there's a reservoir in the water. It's all very controlled, pretty much soil-free. The important thing is nutrients and water. Hi, I'm Lexi. What do yo-yo work in microgravity? I didn't have a lot of time to practice, so here we go, my first yo-yo. So it works, but it's a little bit different. So thanks for the question and letting me find out if they do work. With the year of education on station, NASA's goal was to do what Christa and her optimism did so well, inspire students and teachers to, quote, reach for it, push yourself as far as you can, end quote. For more on NASA's year of education on station, go to www.nasa.gov. For other inspiring NASA happenings, visit science.nasa.gov.