A Stroll Around the Earth
Gemini IV would be a four day flight, to further test spacecraft systems, and with one more twist. One astronaut would take a brief stroll in space.
The Soviets already had done a spacewalk. This was our chance.
Jim McDivitt flew left seat, and Ed White would get to become a human satellite. Before he got that opportunity, however, there was one procedure to be tested. The crew was to attempt to rendezvous with the Titan II second stage.
Both the pilots and Mission Control would get a needed primer in orbital mechanics.
The second stage was ahead of the spaceship. McDivitt attempted to catch up with it by increasing the speed of the craft, just as you would on Earth. Ah, but terrestrial mechanics don’t work in orbit. Increasing speed moved the craft into a higher orbit. In a higher orbit, the speed of the craft decreased. This is because the higher the orbit of a satellite, the slower it needs to move to balance the pull of gravity.
The second stage moved further away.
Mission Control realized that what the crew had to do was drop down to a lower orbit—where they would speed up and catch up with the stage. They did so. When they had caught up, and actually moved somewhat ahead of it, they increased velocity and moved up to the second stage.
They were unable to stationkeep, however, as the learning situation had used too much fuel, and the remainder had to be conserved for the rest of the flight.
The next day, White was ready for his spacewalk. The crew depressurized the cabin, opened the hatch, and using a handheld propellant device called the ‘zipgun’, propelled himself away from the spaceship. He floated freely—although tethered to the craft—and described what a feeling of freedom it gave him. He used the zipgun to maneuver himself around, and found he had no ill feelings at all. He was having a ball. So much so that after 16 minutes, Mission Control called up and told him “Get back in." But White just couldn’t bring himself to do so. After a time, the ground called again with a sterner, “Get back in!"
This prompted McDivitt to advise, “"You better get back in." White begrudgingly acquiesced. He had spent 36 minutes as a human satellite.
The first U.S. spacewalk was a resounding success.
The remainder of the flight proceeded without incident, until the crew attempted to set the computer to control reentry. It shut down. They would have to control reentry manually. As a result, they splashed down 80 kilometers off their targeted landing point, but the pickup task force had already begun moving towards the predicted landing point, and the crew was picked up almost immediately.