November 11th marks the forty-seventh anniversary of the launch of Gemini 12, the last human spaceflight mission before Project Apollo, and the first flight to use underwater training for spacewalking or Extra-vehicular Activity (EVAs).
Aptly named after the constellation with the twin stars Castor and Pollux, Project Gemini used a two-person spacecraft to test the effects of long-duration spaceflight, as well as rendezvous and docking in Earth orbit. Established to bridge the pioneering Mercury flights with the complex requirements of Project Apollo, the Gemini spacecraft was almost twice the size of the previous cramped vessel, and it was launched into space atop the massive Titan II rocket. While “Mercury was a Volkswagen,” explained astronaut Gus Grissom, “Gemini’s a Corvette.”
The cockpit of the Gemini 12 capsule on display at the Adler, like the rest of the Gemini fleet, includes 220 dials, switches, and levers, each within arms length of the astronauts’ seats. Mirrors were mounted in the spacecraft so the astronauts could view and operate the controls behind them.
Over the course of four days, commander Jim Lovell Jr. and co-pilot Buzz Aldrin rendezvoused with an Agena target vehicle and tested new techniques honed for spacewalks.
After nearly twenty-months and nine Gemini flights, NASA was still unable to solve the puzzle of EVAs, a critical issue to tackle before the upcoming lunar missions. As astronaut Jim Lovell explained, “one thing that the early EVA people didn’t realize was that for every action there is an equal and opposite reaction.” Although the majority of EVAs were expected to take place on the Moon, spacewalking capability was important for Apollo emergency plans. For the Gemini 12 mission, NASA drew lessons from scuba diving, including the use of foot and hand restraints as well as underwater training, to deal with the absence of traction in outer space.
During a series of three EVAs, Aldrin successfully photographed star fields with an ultraviolet camera, retrieved a micrometeorite experiment, tethered an Agena target vehicle to the Gemini craft, tested the new foot and hand restraints, turned bolts, practiced hooking and unhooking electrical connectors, and threw out trash, proving that underwater training was an essential tool to the future of human spaceflight.
On a recent visit to the Adler, Lovell reflected that the new EVA training “worked perfectly and this is the major system and technique that is used today by both the Americans and the Russians who are working outside the International Space Station.”
Adler visitors can peer in to the Gemini 12 cockpit in the Shoot for the Moon exhibition.
Written by Teasel Muir-Harmony, researcher at the Adler Planetarium.