Dust Control

Octavio Guillermo Reyes Rodríguez

Pablo Demetrio Flamad Reyes

Blasted by meteor impacts to sizes even smaller than one micron, lunar dust invades and sticks in tiny spaces. Its particles are easily blasted across the lunar surface and to high altitudes by rocket engines. The dust has dielectric properties that cause it to be lifted electro-statically off the surface of the moon to inconvenient locations at inconvenient times.

The threat of lunar dust to human health and spacecraft systems is driving future design and operations of those systems to minimize its effects and mitigate it when present. But how can the dust be mitigated unless we know where the dust is located? It may be too small to see, blending in with the background or hiding in crevices. It would be helpful to identify this dust as early as possible, both inside and outside of lunar spacecraft.

When we first arrived to the moon in 1969 we didn’t expect lunar dust to be a major threat. After analysing many samples back in earth, we are now aware of the challenge regolith will represent in future missions to the moon and beyond. And we need to plan ahead. Introducing Dust Control.

The first step we are taking to reduce the amount of dust met by the astronaut is pointing him to the direction where the least amount of dust is. Given the electrostatic nature of lunar dust we believe it is possible to map the areas with more concentration of it using LDS (Lightning detection system). This system will provide information in real time about the electrical activity in the atmosphere. By using the Forte satellite we can measure different magnitudes, thanks to satellite functionality of carrying three sensors: the broadband VHF receivers, the PDD and the Narrow band CCD-array. This way we could get indication of the zones with more concentration of lunar dust so that our astronauts avoid them.

From here on we can start talking about what happens when the astronaut gets in contact with the dust. Lunar regolith suffers from the harsh conditions of our moon. Given that there is no atmosphere to protect it from ultraviolet sun rays, each regolith dust particle has a net positive charge. This characteristic is what makes it stick so easily to anything astronauts touch it with. We realized the cause of the problem could be the answer to solving it. While searching the web for a way to repel the dust with an opposite electrostatic charge we found out that we weren’t the first ones to think about this solution. Carlos I. Calle and his team have been experimenting at NASA with repealing lunar dust. The method involves providing a three-phase alternating current to an arrange of electrodes on a surface, they call it electrodynamic dust shield or EDS. The current flow creates an electric field around the electrodes that repel the charged dust particles from the surface, thanks to the AC three-phase current creating an imbalance between the electrodes the result are dust particles as small as 10μm in diameter bouncing away from the shielded area. This technology could be implemented on the windows and walls of the lunar lander, encrusted and covered in the hatch seal perimeter, vehicles and space suits. We became particularly interested on this last one. Using Carbon Nanotube yarns as electrode wires embedded into the the suit fabrics and applying a multiphase alternating current voltage signal, the space suit can repeal more than 80% lunar dust with particles between 10-75μm in simulated conditions. This technology is still being tested but it's one of our most suggested solutions. This implementation alone would give the astronaut a great advantage before even going back to the module.

Once the exploration phase is finished we want the astronaut to open the lander hatch and enter into a decontaminating room. This will be a sealed room inside the lunar module. It will represurize and the astronaut will be blown by high pressured air all over so that we can eliminate most of the dust adhered in the astronaut suit. Then he will brush off the remaining dust on the suit and finally the vacuuming and filtering process will begin.

Using GP2Y1010AU0F we want to detect the presence of dust in every stage of the process and display this information on an easily visible LCD screen to the user. This way he will know where the system was more effective and use the data for future improvements.