Electrodes in spacesuits could protect astronauts from harmful dust on Mars

To cite NASA affiliate administrator Jim Reuter, sending crewed missions to Mars by 2040 is an “audacious aim.” The challenges embody the gap concerned, which might take as much as six months to traverse utilizing typical propulsion strategies. Then there’s the hazard posed by radiation, which incorporates elevated publicity to solar particles, flares, and galactic cosmic rays (GCRs). After which there’s the time the crews will spend in microgravity throughout transits, which might take a severe toll on human well being, physiology, and psychology.

However what in regards to the challenges of dwelling and dealing on Mars for a number of months at a time? Whereas elevated radiation and decrease gravity are a priority, so is Martian regolith. Like lunar regolith, dust on Mars will adhere to astronauts’ spacesuits and inflict put on on their gear. Nonetheless, it additionally accommodates dangerous particles that should be eliminated to forestall contaminating habitats. In a current examine, a staff of aerospace engineers examined a brand new electrostatic system for eradicating Martian regolith from spacesuits that would probably take away dangerous dust with as much as 98% effectivity.

The brand new system was designed by Benjamin M. Griggs and Lucinda Berthoud, a Grasp’s engineering scholar and Professor of Area Programs Engineering (respectively) with the Division of Aerospace Engineering on the College of Bristol, U.Ok. The paper that describes the system and the verification course of was just lately published within the journal Acta Astronautica. As they clarify, the Electrostatic Removing System (ERS) they suggest makes use of the phenomenon of dielectrophoresis (DEP) to take away Martian dust from spacesuit materials.

Very similar to its lunar counterpart, Martian regolith is anticipated to be electrostatically charged attributable to publicity to cosmic radiation. However on Mars, there’s additionally the contribution made by dust devils and storms, which have been recognized to generate electrostatic discharges (aka lightning). Throughout the Apollo missions, astronauts reported how the lunar regolith would adhere to their fits and get tracked again into their Lunar Modules. As soon as inside, it could equally keep on with every thing and get into their eyes and lungs, inflicting irritation and respiratory issues.

Given their plans to return astronauts to the moon by means of the Artemis Program, NASA is investigating a number of strategies to forestall regolith from moving into habitation modules—like coating expertise for spacesuits and electron beams for cleansing them. Whereas Martian dust is anticipated to inflict related put on on spacesuits, the scenario is made worse as a result of it might comprise poisonous particles. As Griggs defined to Universe Immediately through electronic mail:

“Past having an abrasive impact on spacesuits themselves, Martian regolith can also be anticipated to current well being points to astronauts. It’s recognized to comprise a spread of dangerous particles which can be carcinogenic or trigger respiratory points, and information from the Pathfinder mission confirmed the presence of poisonous particles similar to chromium. Martian regolith will subsequently require elimination from spacesuits previous to entry into habitation zones on Mars to forestall contact between astronauts and regolith particles.”

The precept behind the gadget, dielectrophoresis (DEP), refers back to the motion of impartial particles when subjected to a nonuniform electrical area. Their proposed Electrostatic Removing System (ERS) contains two parts: a Excessive Voltage Waveform Generator (HVWG) used to provide sq. waves of various frequencies and amplitudes as much as 1000 volts and an Electrostatic Removing System (ERD) consisting of an array of parallel copper electrodes. When the sq. waves are utilized throughout the electrodes within the ERD, a big and ranging electrical area is generated. As Griggs summarized:

“Subsequently, when dust particles are incident on the floor of the ERD, the dust particles are displaced by means of a mix of electrostatic and dielectrophoretic forces (because of the massive electrical area), which acts on charged and uncharged particles respectively inside the dust. This acts to displace dust particles in a course perpendicular to the electrodes, ensuing within the clearing of the ERD floor.”

To judge the efficiency of their proposed system, Griggs and Prof. Berthoud developed an experiment to research a number of key variables. This included the frequency and amplitude of sq. waves, the spacing between the electrodes, the incline of the floor of the ERD, the gap between the electrodes and the dust layer, and the fabric of the floor from which dust is eliminated. Step one was to provide analytical fashions, which was an especially advanced job for this technique, and former numerical fashions weren’t significantly helpful.

“For this work, an easier mannequin was subsequently derived utilizing Couloumb’s legislation and the legislation of dielectrophoresis for a preliminary prediction of the impact of parameters together with the sq. wave amplitude, electrode spacing, and dust-electrode separation (the precise distance between the electrodes and the dust particles they’re performing to take away) on system efficiency,” stated Griggs. The following step was to arrange an experiment that will quantify the optimum efficiency and habits of the proposed system and measure its results. As Griggs described:

“Two metrics have been developed for quantifying and evaluating the system performance throughout testing: clearing efficiency (% of the floor that was clear didn’t comprise dust particles), and clearing price (a normalized price of clearing primarily based on the time taken to go from 5% to 60% of ultimate clearing efficiency). A variety of parameters have been experimentally explored, together with the frequency and amplitude of sq. wave utilized throughout the electrodes. The system was then utilized to eradicating dust from the outer layer of spacesuits by integrating a layer of Ortho-fabric (the outer layer of spacesuits) between the system and a layer of dust particles.”

From their assessments, they discovered that the system achieved an optimum clearing efficiency of 98% when built-in instantly beneath a layer of dust particles. Nonetheless, this dropped off considerably when the outer layer was launched because of the elevated distance between the system and dust particles. Because of this, they conclude that this technique would probably should be built-in instantly into the outer layer of spacesuits to extend efficiency, probably woven into the material itself. The system provides a non-abrasive technique for dust elimination, which is important to future Mars missions.

Nonetheless, as Griggs summarized, additional refinements are required earlier than the expertise can be utilized on future missions. As well as, the potential advantages attain past astronaut well being and eradicating dust from spacesuits:

“This idea has already been explored with success, although by its very nature it compromises the integrity of the outer layer of spacesuit. The expertise subsequently requires refinement earlier than utility on future Mars missions. The expertise gives an acceptable different to the mechanical strategies of dust elimination used on the short-length Apollo missions (brushing and vacuuming), that are unsuitable for longer Martian missions attributable to their abrasive impact on the spacesuits. It’s subsequently additionally a really promising expertise for dust elimination in different purposes similar to dust elimination from solar panels or optical units, which will likely be important in future Mars missions.”