Can u recall the 22-karat gold coins that flew aboard the Space Shuttle Columbia in July 1999? Don’t stress even if you don’t remember. You can take a look at them at the American Numismatic Association’s World’s Fair of Money in Milwaukee, the largest coin show in the nation.

The 12 gold versions of the circulating Golden Dollars will be unveiled at the fair. The 22-karat gold version of the Sacagawea Golden Dollar is made of .9167 (half ounce) fine gold.

Till date, the gold “space coins” has been stored at Fort Knox. They were never seen in public were never sold. This very feature makes them extremely rare.