First, let’s talk about terminology. When we talk about putting on or taking off a spacesuit, we frequently use the terms “donning and doffing.” These are technical terms that are used to refer to the practice of putting on (donning) and taking off (doffing) protective gear, clothing, and uniforms. The normal use of these terms has historically been for legal purposes in the labor relations field, but in the last 50 years, they have fallen into use in the space community. The terms are jargon, and I try not to use them, but all should be aware that they are out there and exist. There are, however, technical terms that I do use. These terms define the components of a spacesuit and often refer to specialized and necessary concepts. So how do you put on a spacesuit? Very carefully! Even in the case of custom-made suits from the Apollo era, astronauts had to practice putting on and removing spacesuits repeatedly to make it a smooth, effortless, and unsurprising enterprise. In the case of an emergency, Apollo astronauts would have only five minutes to get their suits on. That would require them to omit all the testing procedures that are part of the formal dressing. In preparing for flight, astronauts would go through the formal dressing process which would take much longer as each section is checked and rechecked to make certain that it functions as designed.
Step One: Where We All Start Apollo astronauts first started by putting on highly absorbent underwear. They wore these under their suits in case there was an unanticipated bathroom accident. These heavy-duty, space boxer briefs would fill in for an emergency. In addition, they had a urine collection device. This was essentially a heavy, rubber condom attached to a long tube that emptied into a rubberized reservoir. Remember, that all astronauts at the time were men—they adopted technology that long-duration pilots had been using for years. Step Two: Keeping Cool The next layer was a liquid cooling garment (LCG). This is a water-cooled nylon undergarment that looked like long underwear with clear plastic tubes running through it. Attached to the LCG was a biobelt. Biobelts were constructed of a cotton duck base, a fabric similar to an artist’s canvas, with Teflon-coated, Beta-cloth pockets. Fitted into the pockets were tools that helped monitor the physiological functions of the astronaut including an electrocardiograph signal conditioner, an impedance pneumograph signal conditioner, and a current converter. All the electronic life support signals went through the biobelt. Each sensor had to be threaded through the pouches in the belt and then attached with snap fasteners to the liquid cooling garment.
Step Three: Suiting Up At this point, the astronaut would be ready to put on the major piece of the spacesuit, the Integrated Thermal Micrometeoroid Garment (ITMG). The ITMG is the suit that included the pressure layer, the restraint layer, and the white thermal micrometeoroid layer along with the integrated boot. (Conservator Lisa Young will talk even more about spacesuit layers in an upcoming blog post.) Getting into the ITMG was no easy task. The astronaut would have to climb through a back zipper. The opening was a tight fit, and he would need to maneuver his shoulders and hips through the opening simultaneously in order to get his legs, arms, and head into the suit properly. Success was signaled by the feet being in place in the boots and the astronaut’s head popping through the neck ring. Step Four: Getting Connected With the IMTG on, the astronaut would then start to make the electronic and other connections between the Liquid Cooling Garment, biobelt, and the interior of the suit. After connections were completed, work to seal the suit would begin. The astronaut would zip up the pressure zipper with a long extension ribbon that would pull from the front of the crotch to the back of the neck. Step Five: Accessorizing Once the suit was on, the astronaut would add all the final components. Next to go on would be the Communications Carrier Assembly (CCA), also known as the “Snoopy cap” for its characteristic white and brown markings. The CCA held both a microphone and headset close to the astronaut’s head as he moved around. That, too, would connect to a plug within the main suit. Once that connection was made, all that was left was for the astronaut to put on gloves. These were Intravehicular (IV) gloves for launch that had black rubber hands and white wrists that connected to matching red or blue (right and left) aluminum connectors onto the ITMG at the wrists. A second pair of Extravehicular (EV) gloves were used on the surface of the Moon. These gloves had blue silicone fingertips, and the lower fingers and palms were covered in a woven stainless steel fabric, known as Chromel-R. Gauntlets on these gloves covered the wrist connects so that the metal would not heat and cool quickly. Step Six: Headgear The next thing that the astronauts would put on was a clear, polycarbonate, bubble, pressure helmet assembly that fastened to their neck ring and completed the seal for the Apollo spacesuit. While on the Moon, astronauts wore a Lunar Extravehicular Visor Assembly (LEVA) on top of the bubble helmet that acted as both an oversized set of sun goggles and protected the metal components around the neck from direct sunlight. Step Seven: Necessary Baggage The famous photograph of Armstrong, Aldrin, and Collins walking towards the Saturn V launch vehicle before launch shows them carrying small cases. These were ventilator cases that the astronauts used to maintain atmosphere and cooling while on Earth. Once in the command module, they would link to the spacecraft’s life support, receiving good air through the blue connects on their chest and expelling used air through the red ones.
Step Eight: Preparing for the Moon Before going out onto the surface of the Moon, Armstrong and Aldrin put on their EV gloves, lunar overshoes, Portable Life Support System (PLSS), and Oxygen Purge System (OPS). The lunar overshoes had a similar design to the EV gloves, with blue silicone tread that left the iconic footprints on the Moon. The overshoes had the same stainless steel fabric to prevent against punctures along with layers of synthetic materials all topped with white betacloth to insulate against solar radiation. Unlike the gloves, however, the EV boots fitted on top of the integrated boots of the ITMG. The PLSS was the main life support for the astronauts while exploring the surface of the Moon. It supplied oxygen, cool water, and communications. The OPS was an emergency oxygen supply that was mounted on top of the PLSS backpack that would allow the astronauts to get back to the lunar module and to the command module in case of an emergency. Inside the lunar module, the PLSS would not operate until it was in a vacuum. Astronauts remained connected to the module life support while they depressurize the lunar module and until the PLSS began to supply oxygen and cool water to them. That is why there are two sets of connectors on the front of the suit.
If these procedures sound easy to you, imagine that on the ground, the astronauts put on their suits and equipment with the assistance of technicians and it took them a little more than an hour. Now, imagine doing this inside the habitable volume of an Apollo spacecraft or a lunar module with one or two other humans alongside you trying to do the same thing.
Fun Fact: Alan Shepard’s Mercury MR-3 pressure suit looks much different than the Apollo spacesuits. This is because they are functionally, dramatically different. Eight years before Neil Armstrong made the first step on the Moon, Alan Shepard became the first American into space. Shepard’s suit had no liquid cooling layer, only air. Communications were integrated into his helmet, not the main suit. Essentially, Shepard put on a jumpsuit and helmet much in the same way pilots had been doing for decades before. This was okay because Shepard never needed to leave his spacecraft and in total spent approximately 15 minutes in space. There's still time to help us reboot Shepard's spacesuit. Learn about our Kickstarter project #RebootTheSuit.