American Space Suits
Like they always say, you gotta dress for success
PART I: Flight Test thru Skylab
In the early days of flight-testing the rocket planes at Edwards, pilots wore the standard flight gear that fighter and bomber pilots wore, including the regulation coveralls and, of course, leather jackets. As the X-Planes flew higher and faster, though, they were getting into altitudes where pressure suits were required to keep the pilots alive. At first, these were capstan-style, partial-pressure suits, such as the David Clark Co. MC-3 suit & MA-2 helmet worn here by legendary NACA/NASA rocket pilot Joe Walker in the mid-1950s. These suits were worn by pilots flying most of the high-altitude aircraft of the day, including the X-1s, X-2, and numerous operational high-performance aircraft, including the F-104 and U-2. Joe Kittinger also wore a version of this suit during his high-altitude Excelsior parachute jumps from baloons. NASA Photo.
In the late 1950s, the USAF, Navy, and NACA/NASA were flirting with the edge of space with the new X-15 program. The new plane could fly much, MUCH higher and faster than anything else in the sky, encountering new areas of potential physiological peril along the way. The X-15 pilot would need a new suit capable of providing life support at altitudes in excess of 50 mi-in effect, a space environment-while simultaneously providing a comfortable body temperature, protection from any harmful "cosmic rays," and even protection during high-altitude, high-speed ejections if needed. The answer came in the form of a "full-pressure" suit, provided by David Clark Co. (again) in conjunction with development teams at Wright-Patterson AFB in Dayton, OH. The suit, known as the MC-2 (known to the military as Air Force model A/P22S). As the suit was developed, it incorporated an outer layer of a special aluminized fabric to reflect solar radiation, as can be seen here on USAF X-15 pilot Maj. Pete Knight. Each of these suits was custom-fit for each pilot, so Pete's suit wouldn't have fit, say, fellow X-15 pilots Joe Engle or Bill Dana. USAF Photo.
For Project Mercury, NASA needed a suit that could truely go into space. They chose a version of the BF Goodrich U.S. Navy Mark IV high-altitude full-pressure suit, known to NASA as models XN-1 thru XN-4; since they were reworked from Navy suits, NASA engineers often referred to them as "quick-fix" suits. These were broadly similar in appearance to the David Clark X-15 suits above, but were really a different design. It consisted of an inner layer of Neoprene-coated nylon fabric and a restraint outer layer of aluminized nylon. Joint mobility at the elbow and knees was provided by simple fabric break lines sewn into the suit; but even with these break lines, it was difficult to bend your arms or legs against the force of a pressurized suit. As an elbow or knee joint was bent, the suit joints folded in on themselves reducing suit internal volume and increasing pressure. Since the Mercury spacecraft cabin was pressurized, astronauts wore the suits "soft" or uninflated, serving as a backup in the event of loss of cabin pressure. Again, each suit was a custom job; so a taller astronaut, like Deke Slayton (shown), could not just lend a spare suit to 5' 6" Gus Grissom. (Deke was grounded before he could fly a Mercury mission, so he never wore this particular suit in space; for more information on Deke Slayton, see The Original 7 and Detante in Space: The Apollo/Soyuz Test Project.) NASA Photo.
As the American space program progressed into Project Gemini, a newer, more-advanced suit was needed, for several reasons. One was that the missions were going to be longer-up to 2 weeks in duration-so the suits had to be more comfortable. Also, since some Gemini astronauts were going to venture outside to perform spacewalks, they would need a suit that offered increased protection against radiation and micrometeoroid impacts-an extra few layers of armor, if you will. NASA's basic Gemini suit was the David Clark G4C, worn here by Gemini 10 astronauts John Young (Command Pilot) and Mike Collins (Pilot). Instead of the fabric-type joints used in the Mercury suit, the Gemini spacesuit had a combination of a pressure bladder and a link-net restraint layer that made the whole suit flexible when pressurized. The gas-tight, man-shaped pressure bladder was made of Neoprene-coated nylon and covered by load-bearing link-net woven from Dacron and Teflon cords. The net layer, being slightly smaller than the pressure bladder, reduced the stiffness of the suit when pressurized and served as a sort of structural shell, much like a tire contained the pressure load of the inner tube in the era before tubeless tires. The design resulted in improved arm and shoulder mobility. Note that Mike Collins' suit is slightly different, incorporating a few more layers of material to give him added protection during his spacewalks; John's suit is thinner, because as the Commander, he will be staying inside the spacecraft. These suits were flown on most Gemini missions; Gene Cernan's Gemini 9A suit featured extra shielding on the legs & lower torso to withstand the exhaust of the Astronaut Mobility Unit (AMU) rocket pack he was scheduled to test fly, although that never happened in the end. For the 2-week Gemini 7 mission, Frank Borman and Jim Lovell wore the lighter, more comfortable suits pictured below. NASA Photo.
Gemini 7 was to be the longest mission to date, lasting about 2 weeks. NASA knew that the standard G4C, as good as it was, was liable to be a bit cumbersome and uncomfortable in the cramped Gemini cockpit for that length of time, so they decided to give Pilot Jim Lovell (left) and Commander Frank Borman (r) new, lighter-weight suits. (There were no spacewalks scheduled for this mission.) The David Clark G5C lightweight space suit was designed to be easily removed during flight and to provide greater comfort than the standard Gemini space suit. During the flight, for the first time, Frank and Jim were allowed to remove their space suits and spend most of the flight in their long underwear for comfort. This was the only flight for this suit, but lessons learned with it were incorporated into later suits. NASA Photo.
For Apollo 1 and the other planned Apollo Block I missions, the plan was to use a suit called the A1C, a variation of the proven G4C Gemini suit. Here, CDR Gus Grissom gets help suiting up for an altitude chamber test at KSC in Oct. 1966. But the suits were never flown; Gus, Ed White, and Roger Chaffee were wearing these suits when they died in The Fire. But the suits did not burn through-they died when the hoses were burned, and they were asphyxiated. When their bodies were removed from the suits, there were very few burn marks. NASA Photo.
By the time Neil Armstrong, Mike Collins, and Buzz Aldrin were ready to go to the Moon on Apollo 11, NASA had adopted and fully tested the International Latex Corporation (ILC Dover)/Hamilton Standard A7L Apollo suit and the associated Portable Life Support System (PLSS or "Pliss") backpacks. These liquid-cooled, bulky but tough suits were designed for the harsh lunar surface environment, which was filled with abrasive lunar dust, and subject to 400+-deg. F temperature variations between light and shadow. Note that Neil and Buzz's lunar EVA suits have different hose fittings and a little bit more substantial build to them than CMP Mike Collins' suit; they would have to wear the PLSSs and go out and walk on the Moon, and he wouldn't. Once again, each suit was custom-fitted, and each astronaut had 3 of 'em-a primary suit for the flight, a backup suit, and a training suit. NASA Photo.
By the end of the Apollo lunar-landing program, the basic A7L suits had been modified with experience and changing requirements. From Apollo 15 on, they were flying the long-duration "J-Missions," which featured 3 moonwalks, each lasting up to 7 or 8 hrs, and the suits and PLSSs had to be updated accordingly. The result was the A7LB suit, was worn here by LMP Harrison "Jack" Schmitt (l) and CDR Gene Cernan (r) for the last mission to the Moon, Dec. 1972's Apollo 17. Compare the configurations of their PLSS hose fittings on the front of the suits to those on the Apollo 11 crew above. In the center, CMP Ron Evans wears a more basic A7LB CMP suit, with fittings to hook up an Oxygen Purge System (OPS) from one of the LM crewmembers' PLSS backpacks, allowing him to do his SIM retrieval EVA during the trans-Earth coast. The basic A7LB suits, with a few modifications, were kept in use through the Skylab and ASTP programs. NASA Photo.
During one of his EVAs on Skylab 3, Jack Lousma is shown wearing the A7LB Skylab Extravehicular Mobility Unit variant of the suit, along with the Astronaut Life-Support Assembly (ALSA) belt and umbilical that took the place of the PLSS backpacks for these missions. During Skylab EVAs, astronauts also carried a Secondary Oxygen Pack, which was hooked up on the left side of the assembly. While there were a few changes to the outer protective garment, the basic pressure suit inside was the same type that had gone to the Moon. NASA Photo.
CONTINUED....
