What did you develop? 

Our solution is to implement specially shaped holes into the exposed surfaces of the structure in a hexagonal close packed pattern. By using a locking mechanism system, astronauts, or in the future, autonomous construction robots can secure themselves to these holes. They will then be protected from being dislocated from the structure, and able to travel in the path they choose along the structure to the point of destination. The negligible gravity and negligible air resistance environment will also allow for easy transport of large parts while walking, to be attached where needed. A cross section of the holes, and holistic view of the structure with these holes are shown below, and well as the locking mechanism at the base of the astronauts’ shoes and future robots’ appendages. 

Why is it important? 

Since this challenge is looking for ways to facilitate large scale assembly in space, the team decided to explore the current challenge of moving freely through the zero-g environment and access any point of the structure being built. Having easy access will allow humans or robots in the future to transport parts to and build off of specific points on the existing structure, which is an additive process required in any assembly process. 

Currently, when working outside a vehicle in space, astronauts require safety tethers to remain secured to the structure. Tethers of lengths of 26 metres are currently in use in the ISS, and tethers of larger lengths would likely be required for larger projects. This is relatively unfeasible for especially long ranges, and increases the risk with such a long member of being broken. For this reason a new design is being suggested, eliminating the need for a tether and allowing astronauts to remain in contact with the structure. 

By implementing a walkable surface, any surface can be traversed with greater ease than a tether, and also keeping the worker/robot in contact with the ship for the easiest controlled navigation. 

What does it do? / How does it work? 

Operation

The mechanism operates as such:

First, the astronaut will don the space suit, as well as place the locking mechanism onto the boot and a remote control for the locking mechanism on the suit.

When performing the space walk,the astronaut places their feet into the locking area

Then, they will activate the locking mechanism in the boot by pressing the button. Two plates will extend, which prevent the feet from leaving the hole.

When the leg needs to be removed, simply retract the plates. 2 conditions will be required to be met before retraction. 1, if the other foot is not secured: do not retract, which satisfies the safety of the astronauts or robots while using, and 2, the astronaut has pressed the button. 

7 Advantages

1. There are no large structures (like scaffolding) that need to be built, reducing material and cost.
2. Unlike propulsion based locomotion system, this provides much more stability and if autonomous robots are used, their operation is self-sustained with solar power.
3. All the actuation mechanism is in the constructor
4. The locking mechanisms have tear-dropped shaped plates which rotate outwards. This conserves space.
5. If holes are not desired, for example, on the interior of a ship where it may present a tripping hazard, a cover can simply be placed over the hole.
6. In the future, this system will suit autonomous robots well. The potential cumbersomeness of timing the engagement and release of the locking mechanisms is greatly reduced as it is built into the robot operation algorithms.
7. The locking apparatus may be separated from the boot in case the apparatus malfunctions and refuses to unlock.

What do you hope to achieve?

This design hopes to achieve greater ease in walking outside a ship, in turn allowing the construction of large scale structures in space which would require people/robots to freely travel along its exposed surfaces to become more feasible.