The Gemini spacesuit is a spacesuit worn by American astronauts for launch, in-flight activities (including EVAs) and landing. It was designed by NASA based on the X-15 high-altitude pressure suit. All Gemini spacesuits were developed and manufactured by the David Clark Company in Worcester, Massachusetts. G3C and G4C suits The G3C and G4C suits were the primary spacesuits worn for all but the Gemini 7 mission. The G3C consisted of six layers of nylon (the innermost containing a rubberized nylon "bladder") and Nomex, with a link net retaining layer and an outer layer of white Nomex fabric. It had removable combat-style boots, also made of Nomex fabric, along with a full-pressure helmet (containing a set of earphones and microphones) and gloves detachable by improved locking rings that allowed easy rotation of the wrists. On Gemini 3, the G3C suit was worn by both Gus Grissom and John W. Young and was the only flight to use this suit. The G4C suit was identical to the G3C suit, but came in two different styles. Both had additional layers of Mylar insulation for temperature control ( in direct sunlight and in shadow), but the commander's suit retained the removable boots, while the pilot's version had integrated boots and a detachable sun visor which clipped onto the helmet. The G4C suit was worn by all subsequent Gemini crews from Gemini 4 to Gemini 12 (except for Gemini 7) and it was in this suit that Ed White made the first American spacewalk in 1965. A further modification, the incorporation of additional layers in the legs, as well as an outer layer of Chromel-R fabric, was made to the EVA suit worn by Eugene Cernan on Gemini 9A, to accommodate a planned test of the Air Force Astronaut Maneuvering Unit (AMU). On this version, the Plexiglas helmet faceplate was replaced with one made of higher strength polycarbonate plastic. This version was also worn by Buzz Aldrin on Gemini 12 for a similar AMU test, though this test was canceled two months before the mission. G5C suits For the 14-day Gemini 7 mission, both Frank Borman and Jim Lovell wore modified G3C suits, but incorporating several changes: Replacement of the pressure helmet and neck ring with a zippered hood incorporating a clear, fixed polycarbonate visor, with the astronauts wearing modified Navy-style aviator crash helmets that incorporated the communication equipment (microphones and earphones). Additional zippers for