Unlike Redstone or Atlas of Project Mercury, Gemini Titan’s rocket was two rockets in one. The first stage lifted the rocket from the launch pad to a height of 64 km (40 miles), before dropping away to allow the second stage to blast off into orbit.

Gemini IV launched from Cape Kennedy’s Pad 19 at 10:16 a.m. (EST) on June 3, 1965 carrying astronauts James McDivitt and Edward White on a four-day, 62-revolution mission including the first US spacewalk, a major feat in space exploration. 

Building on the success of the first piloted Gemini III mission, NASA prepared to launch its most ambitious flight to date—Gemini IV. During June 1965, two astronauts would not only stay in orbit four days, one would attempt America’s first spacewalk. It was another example of advancing technology enabling new avenues of exploration. Since the Soviet Union launched the world’s first satellite, Sputnik 1, on October 4, 1957, the United States had been attempting to catch up in the space race. The Russians passed the Americans again on March 18, 1965, when cosmonaut Alexei Leonov performed the first spacewalk during the one-day Voskhod 2 mission. However, with Gemini IV, NASA was quickly catching up. 

Read more with Gemini IV: Learning to Walk in Space by Bob Granath, NASA's Kennedy Space Center, Florida.