Smithsonian magazine presents "Ten Enduring Myths About the US Space Program." Of course, the moon landing hoax made the cut but there are several good ones in the mix:

"Alan Shepard is A-Okay."

Several famous inventions have been mistakenly attributed to the space program—Tang, Velcro and Teflon, just to name a few.

Most of these claims have been widely debunked. However, one of the most enduring spinoffs attributed to NASA is the introduction of the expression "A-Okay" into everyday vernacular.

The quote is attributed to astronaut Alan Shepard, during the first U.S. suborbital spaceflight on May 5, 1961. The catchphrase caught on—not unlike the expression "five-by-five," which began as a radio term describing a clear signal.

Transcripts from that space mission, however, reveal that Shepard never said "A-Okay." It was NASA's public relations officer for Project Mercury, Col. John "Shorty" Powers, who coined the phrase—attributing it to Shepard—during a post-mission press briefing.