On This Day in History - August 21, 1965
Titan II rocket launches Gemini 5 from Cape Kennedy Space Center. Credit: NASA
On August 21, 1965 NASA launched Gemini 5 from Cape Kennedy, Florida aboard a Titan II rocket. It was the first long duration space flight and the first test of a fuel cell system that could function long enough to fly men to the Moon and back. Astronauts Gordon Cooper and Pete Conrad spent 8 days in orbit circling the Earth 120 times. The mission was important for its experiments in the effects of long-term weightlessness. Gemini 5 set a new human spaceflight endurance record, exceeding the Soviet record of 5 days.
Conrad & Cooper pictured before launch (above) and just before hatch closure (below.)
The Gemini program pioneered the use of fuel cells in space, a similar technology was subsequently used in the Apollo and Space Shuttle programs. A fuel cell is like a battery, in that it uses a chemical reaction to create an electrical current. Fuel cells made long duration manned spaceflight a reality.
The new fuel cells required cryogenic gases to work. Two hours into orbit the Gemini 5 crew noticed the pressure in their cryogenic oxygen was falling. The oxygen level eventually fell below the specified limit, forcing the crew to power down the spacecraft to conserve what power they did have. They had to remain in this this low power state to stay in orbit and to reach their goal of 8 days. The crew was able to take photographs of Earth from orbit, but for the most part it was long and tedious for the crew in a capsule which was smaller than the front seat of a Volkswagen Beetle. Astronaut Pete Conrad would frequently call the Gemini 5 mission “Eight days in a garbage can.”
Cooper and Conrad after boarding the Gemini 5 spacecraft, August 21, 1965. Credit: NASA
The Gemini 5 crew was meant to complete a maneuvering exercise around a specially designed 30-kilogram target alternatively known as Rendezvous Exercise Pod or Radar Evaluation Pod (REP). The REP was fitted into a special compartment in the aft adapter module of Gemini 5, from where it would be released once in orbit. To guide itself toward the target, Gemini 5 was equipped with a new rendezvous radar. On day 2, the new fuel cells started failing which resulted in the planned rendezvous exercise being cancelled. This gave a young astronaut named Buzz Aldrin an idea to design a “phantom rendezvous” exercise, where Cooper and Conrad would rendezvous not with an object but with a fixed point in space.
The Gemini 5 capsule would return to Earth on August 29, 1965. Due to a computing error, the crew landed 80 miles short of the planned landing point in the Atlantic Ocean. The crew and capsule were recovered by the USS Lake Champlain. As of 2006, the Gemini 5 spacecraft is on display on loan from the Smithsonian at the Space Center Houston, in Houston, Texas.