The 1920s were the fledgling years of the real Golden Age of space travel, which lasted until the first few moon landings. Rockets were in all the news. Buck Rogers and Flash Gordon were every red-blooded kid's heroes at the same time Robert Goddard was being ridiculed in snarky articles in the New York Times—but being lionized by every popular magazine in the country as the "moon rocket man". The newsreels were filled with exciting scenes of Max Valier's rocket-propelled aircraft, sleds and railroad cars while every science writer in the world was working like mad to get stories about space travel into print. Always on top of things, scifi pioneer Hugo Gernsack reprinted this chart in the March 1929 issue of Science & Invention. He took it from a German magazine, Das Buch fur Alle. The illustration is probably by the Rohmer brothers, who specialized in depicting Valier's spaceship designs (two of which can be seen zooming at the top of the chart as numbers 14 and 16).