First Mercury, then Gemini … By Gray Rinehart | April 8, 2009 - 10:10 am |February 12, 2013 Space Forty-five years ago today — April 8, 1964 — mission GT-1, the unmanned Gemini-1, launched to test the Titan-II launch vehicle. (NASA Image. Click to enlarge.) (Access the original image here.) by Tagged launch, nasa, rocket, space history, titan. Bookmark the permalink.