Repeat: The American professor Robert H. Goddard had worked on developing solid-fuel rockets since 1914, and demonstrated a light battlefield rocket to the US Army Signal Corps only five days before the signing of the armistice that ended World War I.
The American professor Robert H. Goddard had worked on developing solid-fuel rockets since 1914, and demonstrated a light battlefield rocket to the US Army Signal Corps only five days before the signing of the armistice that ended World War I.