We as VPN, choose this challenge because we thought this was a challenging one to work on, in which we think we could develop an innovative solution. Apart from that this was a challenge that we think we can fit well as a team.

INTRODUCTION

The challenge chosen by the team is Dust Yourself Off, which consists of mitigate and remove the lunar dust and identifying places where it affects both, the astronauts and the spaceship's circuits, so it does not compromise the state of the mission.

The lunar dust is composed mostly of metal oxides, mainly iron, silicon and magnesium dioxides. Its size varies from stones that are visible to the human eye to size orders of micrometers (average 40-160μm), which makes the dust very invasive and difficult to mitigate and detectate.

The project is based on creating different devices and systems, that makes up an efficient cleaning and mitigation method to reduce as much dust as possible, before astronauts begin the return to Earth.

These devices are focused on future missions, which aims to have a longer space exploration and an increased exposure on the lunar soil.

The main objective took on the project is to minimize contact between the astronaut and the dust (it causes health damage according to data provided by NASA), as it penetrate the astronaut's suit and any slot the spaceship may have, damaging sealing systems, circuits and important parts.

Devices developed for the mission:

FOR THE ASTRONAUT

An interchangeable modular dust armor will be developed, which will be placed above the astronaut's main suit.

This will be conformed in the following way, using a pressurization system of a gel between two textiles (which will be of the same microfiber as the astronaut's main suit). The dust will penetrate the textile (outside of this system) reaching the gel, getting attached to it so that the dust will not move out or continue advancing.

The properties of the gel are based on the fact that the fluid we will use is of high viscosity, so it will obstruct the dust (or decrease its inertia).

This gel will be organic based, boosted with a compound (copper Cu0) so that at the time that the dust penetrates the outer layer of the system and enters the gel, the copper that will be suspended will react with the dust. The silicon (SiO2) itself being in an oxidation state will be reduced, generating a reduction of the oxide of the metals that the dust is conformed of, causing a difference in the initial temperature of the gel, which with thermal sensors we will detect these differences of temperature.

Silicon will be used for the reaction because it is the compound with the highest concentration in the dust about 45% of its composition. Creating ranges of saturation levels in each module of the armor that will automatically warn the most affected areas and sent an alert, to the astronaut and those responsible for carrying out the mission.

ARMOR MODULES

The armor will have a main structure that will be composed of a chest, arms, legs (which reaches the upper area of the boots).

This will come inside in a special chamber attached to the lunar module, which one of the purpose is being a place where astronauts can exchange armor modules. This armor will be coupled to the main suit, it will also have joints where patches of the same material will be attached, and the main armor system, with the advantage that they will be quickly decoupled and coupled. These will only be used as a first barrier preventing dust from damaging the main armor quickly, which would cause an exposure to the astronaut's main suit to dust, and subsequently to the astronaut. These will be exchanged during the mission if the circumstances are indicated through the alerts that the astronaut and those in charge of controlling the mission will receive. The patches that are exchanged will be cast away in a special compartment avoiding contamination of the lunar soil.

For boots we will use a detachable sole technology. The purpose of this sole will be to not allow the astronaut's boot to be directly contaminated, which will then be in an environment close to the astronauts. These soles will be discarded at the end of the mission or at the time they are damaged and have to be exchanged for a spare in good condition, being confined in the same way as the patches.

MODULES (MAIN ARMOR STRUCTURE)

Arms:

• Full sleeves (from shoulders to knuckles)
• Joints by velcro on the shoulders and hands.
• It is placed manually.

Chest::

• Chest with space for radio systems, complete up to V-shaped crotch.
• Joints by velcro around the entire chest and on the modules of the legs.
• It is placed manually.

Legs-feet:

• Full leg and upper foot.
• Joints by velcro between parts of the same module.
• It is placed with the help of “tweezers” to adjust the velcro.

CLEANING CHAMBERS

The Moon module will have a double cleaning chamber, which will be deployed to the lunar surface. These cameras will be separated by a sliding gate, and in this separation there will be several layers of bristles, which will brush the surface of the astronaut’s suit as the astronaut go from one chamber to the other.

The connection between this double chamber and the lunar module is through an elastic tube, which will be protected by another tube that will be retractable.

This inner tube will have internal bristles, which will clean the residual dust in the astronaut’s suit while the astronaut go through it, contributing to the cleaning and decontamination of the environment.

The first chamber will have a pressurization system from above, creating a pressure difference between the top and the bottom of the chamber causing the dust to move towards the bottom of it, so that any contamination in the environment will be accumulated on the floor, which will be a grid that below will have a layer of a patch system like the one mentioned above for the armor, which means that the gel will accumulate dust from the chamber environment.

To perform this action, a higher pressure must be generated in the second chamber because that prevents dust from passing into it. Otherwise, the pressure generated in the first chamber could push the dust into the other chamber.

The second chamber will have compartments where spare parts of the patches and the main armor that make up the dust armor will be stored. It will have a system that helps the astronaut with the coupling of the modules to maximize efficiency when the astronaut have to exchange patches. These patches have the objective of making the astronaut lose as little time as possible in case the astronaut have to exchange modules and concentrate on what is really important, the mission.

Protection at critical points:

In critical areas there will be double walls, these will be filled with the aforementioned gel. This will prevent dust from leaking heavily, within this area.

Here, thermal sensors will also be available, which activate a mechanism that emits ultrasound waves (in the 20-80 kHz frequency range). These are emitted from various sources, generating interference between them. This causes a difference in pressures in the medium (in this case the gel), and in the points of destructive interference called nodes, there is physical equilibrium so that the dust that is in one of them will remain in it, and those that are close will move towards them.

By changing frequencies, we can move the nodes, pushing them against the outer surface, and controlling their entry.

By using this acoustic wave system, we are using a system that works at a lower power compared to other types of waves, such as the electromagnetic ones that in turn can have a negative impact on controls and devices of the ship and the suit Space Astronaut.

The areas where this would be implemented are hatch frames, points of possible dust filtration in circuits, and where it is considered necessary or convenient.

To the future!

• Investigate ways to make the gel more practical and more efficient.
• Optimization of spaces in the chambers.
• Improving bristles and cleaning tubes.
• Improving armor joints.

Sources:

• (20/10/19)The Chemical Reactivity of Lunar Dust Relevant to Human Explorationof the Moon (Online in: https://www.lpi.usra.edu/decadal/leag/DavidJLoftus...)
• (20/10/19)Lunar sourcebook : a user's guide to the Moon (Online in: https://www.lpi.usra.edu/publications/books/lunar_...)

#gel #ultrasoundwaves #armor