June 21

1781: Siméon-Denis Poisson, mathematician and experimenter in electromagnetic theory, was born. 1788: The U.S. Constitution went into effect when New Hampshire became the 9th state of ratification. 1874: Anders Ångström, after whom the unit of wavelength is named, died. 1893: The first Ferris wheel premiered at Chicago's Columbian Exposition. 1913: Georgia Broadwick became the first woman to parachute from an airplane. 1945: U.S. troops took the island of Okinawa. 1948: The first successful long-playing microgroove phonograph records were introduced to the public. 1948: The Small-Scale Experimental Machine (SSEM), the first stored-program computer, ran its first program. 2004: Mike Melvill became the first civilian to pilot a craft into space, in Rutan's SpaceShipOne. 2005: The world's first solar sail spacecraft, funded by the non-profit U.S. Planetary Society, was placed in orbit.