Hedy Lamarr's deadly weapons

More than just a Hollywood icon, she was a pioneer of military technology, says Edward Helmore

In an extraordinary marriage of beauty and brains it turns out that Hedy Lamarr, to many one of Hollywood's most glamorous actresses, was an accomplished inventor who developed an early guidance system for torpedoes that was later developed to become the basis for some of the world's most secret communication satellites.

In the odd tradition of celebrity patents - one that includes Harry Houdini's diving suit, Lillian Russell's trunk-cum-dresser, Zeppo Marx's cardiac wristwatch and "Mark Twain's Patent Scrapbook" - the little-known and improbable tale of how Lamarr bridged the worlds of showbiz and technology to become a pioneer of advanced weaponry was recently unearthed by Hans- Joachim Braun, a history professor at Universitat der Bundeswehr in Hamburg.

As a teenage actress in pre-war Berlin, Hedwig Eva Maria Kiesler, who would later be given the name Hedy Lamarr by the Hollywood film mogul Louis B Mayer at MGM, showed the world her acting skills and much of herself in the 1933 Czech film Extase (Ecstasy). Her performance attracted Fritz Mandl, a powerful Austrian arms dealer, who won her hand and presented her as a hostess of Viennese society, entertaining such figures as Hitler and Mussolini.

In 1937 the two divorced, Mandl becoming an adviser to Juan Peron in Argentina, while Madame Mandl moved to Hollywood where she became Hedy Lamarr and starred opposite Clark Gable and Spencer Tracy in such films as Samson and Delilah and Comrade X. There she met the second of her six husbands, the avant-garde composer George Antheil, best known for his Futurist composition Ballet Mechanique, which required 16 synchronised player-pianos and caused a sensation when it was first performed in Paris in 1926.

Antheil, who was working as a film-score composer, had written a series of advice columns to the lovelorn in Esquire and published a book, Every Man His Own Detective: A Study of Glandular Endocrinology.

In the summer of 1940, the 26-year-old film beauty met Antheil at a dinner party and apparently approached him to inquire how she could enlarge her breasts.

The subject soon turned to weaponry when she revealed she was considering leaving Hollywood to work for the National Invention Council in Washington DC.

Lamarr had the idea that a torpedo's radio guidance signal could not be jammed if the signal was hopped across at seemingly random frequencies at split-second intervals. Would-be eavesdroppers would hear only unintelligible blips, and attempts to jam the signal would succeed only at knocking out a few small bits of it. Antheil's contribution was that the frequencies could be switched in much the same way as he co-ordinated the player-pianos in his ballet using slotted paper rolls.

Based upon the 88 keys on the piano, the couple submitted their "Secret Communications System" to the Invention Council and were granted a patent two years later. But the clash of cultures proved too much for the Navy, which shunned the idea, put off partly by the idea of having piano rolls in their torpedoes, as well as the problems of radio waves penetrating the water.

The Lamarr-Antheil patent expired in 1959, just three years before frequency- hopping was first used on ships during the Cuban blockade. Since then it has become the basis of modern anti-jamming applications, such as the $25bn US Milstar defence communications satellite system.

In her Hollywood days, Hedy Lamarr was often quoted as saying, "Any girl can be glamorous. All she has to do is stand still and look stupid." Glamorous she was, but stupid she wasn't.