Rockets can never work

On January 13, 1920, the New York Times ridiculed the ideas of Robert H. Goddard. Goddard, a physicist and pioneer in the field of rocketry, was at the time sponsored by the Smithsonian. Nonetheless, the Gray Lady argued in an editorial that thinking that any sort of rocket could ever work int he vacuum of space is essentially foolishness and a blatant disregard for a high school understanding of physics. The editors even went into reasonable detail in order to debunk Goddard.

Luckily the Times was willing to print a correction. The only hitch: They printed it the day after Apollo 11's launch in 1969. Three days before humans first walked on the moon, they recanted their editorial with this bit of understatement:

Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th century and is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.

Samuel Arbesman, The  Half-Life of  Facts: Why Everything We Know Has an Expiration Date (New York: Current, Penguin USA, 2012), ch. 9 (citing "A Correction," N.Y. Times, July 17, 1969).