An exploration of Spacesuit joint design
The next several decades will see humanity push further into space. Whether on the Moon, in orbit or even on Mars, we will need to venture out into the environment. The spacesuits in use today are old and in need of development to improve this experience. This project explores the use of origami in creating a joint with greater mobility, thereby allowing the suit to operate at a higher pressure. In doing so, astronauts will no longer need to purge nitrogen before a spacewalk.
Chosen folding pattern
The great challenge of testing and building this structure is the requirement to hold pressure. Therefore, the joint would have to be built with constraints to ensure the shape is conformed to.
This project chose the neck joint as the point of focus, though could apply to any other joint. Currently absent in spacesuits, this was chosen due to the high mobility of the neck as well as looking at a potential future of compressive space suits.
The challenge of space suit joints is to ensure a minimal change in interal volume during any deformation. Due to the pressure imbalance with the outside this requires mechanical work to be done to deform the volume. The pattern (left) was chosen as it has the property of allowing all of the motion required (flexion, extension, rotation, etc.)
Final Prototype and Test Rig
The final test rig was constructed from a one sided TPU coated nylon with stiffening spars added provide added structure to the folds. While not a perfect construction the video below shows its movement and functionality under a small amount of pressure.
The nodes were left soft to allow for greater mobility. Another iteration would make a large number of changes including:
- Improved seals top and bottom for control of internal pressure
- New spar attachment method(likely as a separate restraint layer)
- Connections between the spars to better control the node shape
- pressure gauge
- Method of measuring force applied and displacement/rotation
This project explored a potentially interesting joint design and construction. However I was unable to take the project far enough to truly explore the viabilty of the concept. It was not taken far enough to begin to take measurements of force and displacement, nor on comfort and fit. Methods of prototyping and design decisions made at the early stage also should have been augmented with more simulation of the shape. Aspects that have yet to be given more than cursory exploration include:
- The number of nodes per layer (related to the amount of rotation the shape can do)
- The number of layers in the joint
- What is the ideal neutral state of the joint. How ‘compressed’ should it be. (this is the vertical height of the joint in the test rig above)
Further exploration, research, and design should be applied to asking the question of what a lightweight, ‘high’ pressure spacesuit joint allows astronauts to do. Feasibly an astronaut could just put on the suit and go out on a spacewalk, or a lunar stroll. This calls back to my initial interest in this project which was the question “What if we could bring spacewalking closer to scuba diving?”. Hopefully I will return to this project soon to better answer that question.