During the heady time of the space race during the 1960s the key element of spacewalking, in NASA parlance Extravehicular Activity or EVA, had to be made real. The first American spacewalk took place on June 3, 1965, during Gemini 4 now just fifty years ago. NASA devised Project Gemini specifically to advance this operation, as well as rendezvous and docking and long duration spaceflight.
Initiated in the fall of 1961 by engineers at Robert Gilruth’s Space Task Group in cooperation with McDonnell Aircraft Corporation technicians (builders of the Mercury spacecraft), Gemini started out as a larger Mercury Mark II capsule but soon became a totally different proposition. It could accommodate two astronauts for extended flights of more than two weeks. It pioneered the use of fuel cells instead of batteries to power the ship, and it incorporated a series of other modifications to hardware. Its designers even considered using a paraglider being developed at Langley Research Center for “dry” landings instead of a “splashdown” in water and recovery by the Navy.
The entire system was to be launched into orbit by the newly developed Titan II launch vehicle, another ballistic missile developed for the Air Force. A central reason for this program was to perfect techniques for rendezvous and docking, so NASA appropriated from the military some Agena rocket upper stages and fitted them with docking adapters.
Problems with the Gemini program abounded from the start. The Titan II had longitudinal oscillations, called the pogo effect because it resembled the behavior of a child on a pogo stick. Overcoming this problem required engineering imagination and long hours of overtime to stabilize fuel flow and maintain vehicle control. The fuel cells leaked and had to be redesigned, and the Agena reconfiguration also suffered costly delays. NASA engineers never did get the paraglider to work properly, and eventually they dropped it from the program in favor of a parachute system like the one used for Mercury. All these difficulties shot an estimated $350 million program to over $1 billion. The overruns were successfully justified by the space agency, however, as necessities to meet the Apollo landing commitment.
By the end of 1963 most of the difficulties with Gemini had been resolved and the program was ready for flight. Following two unoccupied orbital test flights, the first operational mission took place on March 23, 1965. Mercury astronaut Gus Grissom commanded the mission, with John W. Young, a naval aviator chosen as an astronaut in 1962, accompanying him. The next mission, flown in June 1965, stayed aloft for four days, and astronaut Edward H. White II performed the first American extravehicular activity (EVA), or spacewalk.
This failed to be the first spacewalk, however, because Soviet Cosmonaut Alexei Leonov beat White out at the first spacewalker. During the flight of Voskhod 2 on March 18, 1965, he exited the spacecraft and floated outside the spacecraft, secured to the spacecraft by only a safety line. He pushed away from the vehicle and drifted out to 17.5 feet (5.3 m) before returning to the spacecraft. A tense few moments ensured when Leonov found his spacesuit too rigid to reenter the airlock. He solved the problem by bleeding air out of his suit and reducing its size so that he could fit back through an inflatable airlock. As Leonov wrote about this experience:
During my training for this mission, I did a drawing showing how I imagined myself walking in space high over the planet Earth in the outer cosmos. The dream came true, and space walking became a reality with my EVA on Voskhod 2 in March 1965. During the space walk, I was exposed to the vacuum of space for some 20 minutes, considerably longer than expected, due to problems re-entering the spaceship. The pressure difference between air in my space suit and the vacuum of the cosmos expanded my space suit and made it rigid, and I had to force some of the air out of the suit in order to close the lock’s outer hatch.
Although the Soviets trumped the Americans with the first EVA, the Gemini program soon demonstrated considerable capability. Eight more missions followed through November 1966. Despite problems great and small encountered on virtually all of them, the program achieved its goals. Additionally, as a technological learning program, Gemini had been a major success, with 52 different experiments performed on the 10 missions.