By tradition, space shuttles are named after exploratory or research sea vessels. The original 18th century Endeavour, under the authority of Captain James Cook, collected valuable astronomical data and sailed to New Zealand and Australia on its three-year voyage. And of course, that other Endeavour took a British spelling (with the -our ending, like honour and colour). It wasn't until American lexicographer Noah Webster published his Compendious Dictionary of the English Language in 1806 (which included a number of his own spelling reforms) that American spelling became consistently differentiated from that of British spelling.