Then & Now: Educator Resources
via science.nasa.gov
Short excerpt below. Read at the original source.
Explorer 1 Explorer 1 About Explorer 1 Explore As One Galleries Image Gallery Video Collection History History Overview Complex 26 Journey of Discovery Then and Now Van Allen Belts Resource Resource Overview Their Own Words Submenu Title Stories Celebrating 60 Years of Innovation, From Explorer 1 to Today A satellite orbiting Earth used to be […]