Extra-terrestrially sexy! Kate Upton went where no bikini model has ever gone before for Sports Illustrated's 50th Anniversary Swimsuit Issue -- showing off her world-famous curves in a gold Target bikini in a weightless Zero G airplane.

Floating in the air (but managing to stay inside that skimpy suit!) Upton and an expert crew shot above Cape Canaveral, Fla. (near NASA headquarters, natch) back in May 2013. The bubbly blonde, 21, also scored the flipside cover of the landmark issue (Chrissy Teigen, Nina Agdal, and Lily Aldridge don the cover of the other side, which was revealed last week.)

Even more extraordinary? Upton's gold bikini is available at Target for a cool $35.

Watch a video of Upton's amazing Zero G bikini shoot now!