NASA Photo ID: 65-H-441
Date Taken: 03/23/65
In the white room atop the Gemini launch vehicle, Astronauts John W. Young (left) and Virgil I. (Gus) Grissom prepare to enter the Gemini spacecraft. Astronaut Thomas P. Stafford, GT-3 backup pilot, along with spacecraft engineers and technicians look on. The National Aeronautics and Space Administration's GT-3 flight was launched at 9:24am, EST, Tuesday, March 23.
Source: NASA photo in my possession