Innovation in Engineering: Apollo 11 Space Suits

When engineers took on the task of putting a man in space and on the moon, they knew that there would be an uncountable number of challenges ahead of them. They were breaking new ground but were also creating and discovering everything as they went along. There were many spacesuits before the Apollo missions, many of them prototypes or concepts, but very few were used in space missions. But the Apollo suit would have to be much different from all the rest as it had to go to a place no spacesuit was ever designed to go to, the moon. In this report, I will outline the functions the spacesuits needed to carry out. What type of environment they need to survive in. And what was installed on these suits to allow them to carry out and survive these functions and environments.

The moon’s surface does not contain very many properties similar to those we experience on earth. For starters, it has no atmosphere and therefore no gases are contained inside the non-existent atmosphere. There is no oxygen for the astronauts to respirate because of these properties. Since there is no atmosphere on the moon, it basically shares the same properties at space. Because of this, the moon’s surface is a vacuum. With that being said, the pressure on the moon’s surface is 1.3x10-11 Pa. The earth's average atmospheric pressure is 1.020x105 Pa. That’s 8 Quadrillion times higher than the pressure on the moon. The temperature of space is about 270o C in direct sunlight and -170o C in no sunlight. We do not experience these harsh temperatures on earth as our atmosphere protects us. It keeps the temperature cooler in direct sunlight and warmer when not in sunlight e.g. night time.

The engineers tasked with making the spacesuit for Apollo 11 would have to effectively make a mini atmosphere around the astronauts, but still, be flexible enough to carry out tasks on the surface of the moon.

Spacesuits before Apollo 11 were basically upgraded high altitude suits. Meaning that they allowed the astronaut to breathe in the cockpits of their spaceship during space flight. All models did have a small bit of an artificial atmosphere present inside them, and some incorporated built-in radio communications devices. One thing all spacesuits used in spaceflight before Apollo 11 have in common is the umbilical cord. The umbilical cord was the term given to the tube that connected the spacesuit to the ship. Through this tube, oxygen mixtures were passed through to allow the astronaut to breathe, as well as radio communication wires and vital information. Spacewalks were essentially when an astronaut exits a spacecraft into space, purposely. This was the beginning of the Apollo 11 space suit as many of the same requirements were needed for both types of spacesuits. These spacesuits needed to be able to withstand small meteorites hitting off them along with creating a small atmosphere inside the spacesuits and supply the astronaut with oxygen, cooling, and radio communications. But these suits still had the umbilical cord design incorporated. This was something that had to be scraped for the Apollo 11 mission.

The company ILC Dover, a bra-making company was chosen from a list of candidates to design and create the spacesuit while The Hamilton Standard was chosen to create the life support system, aka the ‘backpack’. For this many, more innovations would be needed to create this masterpiece of engineering. The spacesuit would have to be a soft design for the amount of flexibility that they needed to complete the tasks they were required to do. Spacesuits at the time were between ideas of having a hard design, being mostly made up of metal, or a soft design which would be mostly all fabric. Hard designs would be easier to create and seal effectively, and engineers would be more used to working with metal. But the soft design was superior as it allowed the astronauts greater mobility which would be needed for scientific research and take-off and landing. The spacesuit's oxygen supply would be very different to the ones that came before it. This time it had to be fitted inside a ‘backpack’ (Life support system) that the astronaut had to wear. The oxygen tanks and filtration system were located inside the backpack and was connected to the main spacesuit by tubes. The tubes had a dial on the side of it to direct the flow, there where two options, 50% to the helmet and 50% to the arms and legs. Or 100% to the helmet. The backpack was capable of supplying 2.8Ls-1 or 5.7Ls-1 of oxygen to the suit. The suit could also be hooked up to the oxygen supply of the spaceship, but that function was hardly ever used. The suit also had to protect the astronaut from small asteroids or micrometeorites. The suit's fabric had many layers of different materials to protect against this and other effects of space. The outside layer had a TeFlou® fabric which was very good at controlling and insulating the user against solar radiation. The second layer was something called ‘Super Beta Cloth’. This material could withstand the heat of up to 650oC. This was a must after the fire that occurred in the cockpit of Apollo 1 which killed all three astronauts. The rest of the layers were made up of alternating Mylar® film, Dacron®, and Beta Marquisette, which all worked really well at shielding the astronauts from solar and galactic radiation.

The helmets they had consisted of two parts. The first was the original glass ‘fishbowl’ (pressure helmet) that covered all of the astronaut’s entire head and connected with special fittings that would hold the seal. This inner part had a small valve that could be used to pass food through in case there was an emergency and they couldn’t remove the spacesuits. The second part was the extravehicular visor assembly which went over the pressure helmet and had multiple visors made of polycarbonate and gold-coated polysulfone to protect the astronaut from solar radiation and the intense light from the sun.

The spacesuits were made of multiple layers, one of which went on before the actual spacesuit itself. Under the heavy spacesuit made up of the material referred to in the previous paragraph, an overall layer went on the astronauts. It was called the heat exchange system and was like a modified set of ‘long johns’. The fabric would be covered in small plastic tubes. Through these plastic tubes, cold water was pumped from the backpack to cool down the astronaut from his own body heat. This worked in much the same way as a refrigerator does. In this layer, there was also a system for collecting urine. As the astronauts didn’t have any other means of urinating, a tube was placed inside the astronaut’s urethra (much like in hospitals for bed-bound patients) and was piped out to a collection system in the astronaut’s backpack. As for defecation, a return to the astronaut’s younger years was needed, as they were issued adult-sized diapers for the trip. There was (and still is) no better way to deal with the waste.

This would be the first time that man would have stepped on the surface of any other planetary object in the universe besides Earth. Therefore, footwear would have to be provided. Something that never had to be too developed in the past as other spaceflights didn’t require any landings. The shoe sole was made of a molded silicone rubber while the upper parts were made of more Beta Cloth with layers of aluminized Mylar® and Dacron®. These boots were not the only pair the astronauts wore. Inside these ‘lunar boots’ they had their ‘pressure garment boot’ which was the actual boot that sealed in the astronaut. The lunar boot was more for added protection against sharp rocks from bursting the astronaut's pressure suit.

With all these innovations that were all developed specifically for this landing, engineers were able to supply the astronaut with enough protection to make it to the moon and back, safely.

Conclusions

Spacesuits came a long way in the space of ten years before the Apollo 11 mission. But after that our designs have stayed basically the same despite some upgrades or modifications. This is one of the more significant innovations in the engineering of all time. It allowed us to explore beyond our planet and step onto others. Overall the new spacesuit design was a huge success. Not only did it advance our understanding of materials and fabrics, but it also allowed to ask questions about our anatomy in an environment other than our own. A study that’s continuing to this day.

References

1. ILC Dover, 2013. Apollo Space Suit. 1st ed. Frederica, Delaware: ASME.
2. Jaeger, J., 1953. The Surface Temperature of the Moon. Australian Journal of Physics.
3. Kenneth S. Thomas, H. J. M., 2012. U.S. Spacesuits. 2nd ed. Chichester: Praxis Publishing.
4. NASA, 2006. Apollo 11 Lunar Space Journal.
5. Available at: https://www.hq.nasa.gov/alsj/a11/A11NAAFlownSuit.html [Accessed 18th October 2019].
6. NASA, 2019. Apollo 11 spacesuit and glove. [Image]
7. Available at: https://history.nasa.gov/alsj/a11/images11.html#Suit [Accessed 18th October 2019].