Erika Alvarez is the Lead Systems Engineer for NASA's Space Launch System — so what does a lead systems engineer do? Get the details and learn more about SLS in our newest episode of NASA's Rocket Science in 60 Seconds! go.nasa.gov/2WPOGgf | NASA's Marshall Space Flight Center

Today, in 1969, Apollo 11 splashed down in the Pacific Ocean marking the end of one of the most historic human spaceflight missions to date. Here's a look back at all of our Apollo 50th celebrations, honoring the men and women that made the Apollo missions possible. | U.S. Space & Rocket Center

The core stage for NASA's Space Launch System is completely assembled! ...but wait a second — what exactly is the SLS core stage again? Learn more in our newest episode of Rocket Science in 60 Seconds! | NASA's Marshall Space Flight Center