Abstract

The project aim was to design a system which provides an effective and efficient way of detection and disposal of a lunar dust particles. Ionizing particles could help to remove even the smallest of them from the space suit. After the dust is drawn off from the cleaning module, risk of electronic breakdown and health hazard is significantly reduced.

Motivation

Moon dust is an insidious substance. Astronaut Neil Armstrong nearly fell down, slipping on it. Its smallest particles made their way through the airtight joints of the space suits, blocking the them so that it became difficult to bend the arm at the elbow. Abrasive dust made the helmets frosted. The spacesuits became almost worthless after only three walks on the Moon. The optics of photo and television cameras suffered, instrument sensors clogged. Once through the airtight hatch into the landing module, and from there into the orbital module, the dust irritated the eyes of astronauts. There was a pungent smell in the spaceship, reminiscent of a gunpowder. According to some reports, moon dust is poisonous. It caused an allergy of the Apollo 17 crew members on their way back to Earth.

The main question – how to prevent it?

Solution

After the astronauts enter the airlock and pressure is normalized, high pressured gas is used to blow away the dust particles from the spacesuit. The particles are then ionized using EUV rays (photo electron effect) and later captured using a negatively charged plate; the positively charged plate are used to attract the emitted electrons. At this point, it is safe for astronauts to leave the airlock and enter further section of the vehicle while the dust is drawn out through a small opening.

Analysis

The moon dust is a composite of many chemical elements, which are distributed as:

• 50% SiO₂
• 15% Al₂O₃
• 10% CaO
• 10% MgO
• 5% TiO₂
• 5-15% iron

Oxygen requires the highest energy levels to be ionized compared to other elements in the list. Therefore, the ionization energy of the lunar dust particle could be approximated to ionization energy of the oxygen molecule.

Ionization energy of the oxygen molecule is given as:

I(O2) = 12.077 eV

To make sure that the ionization process will be effective we used higher value of ionization energy:

E = 15.000 eV

The wavelength of the ionizing radiation then could be calculated:

λ = (h * c) / E

λ = 82.66 nm

The calculated wavelength corresponds to a wavelength of extreme ultraviolet (EUV) light spectrum.

Thus, the lunar dust could be ionized using EUV light source.

Resources used from NASA:

• Heiken, Vaniman and French (1991) Lunar Source Book. New York: Press Syndicate of the University of Cambridge. (https://www.lpi.usra.edu/publications/books/lunar_sourcebook/pdf/LunarSourceBook.pdf )
• Loftus, D.J. et al ‘The Chemical Reactivity of Lunar Dust Relevant to Human Exploration of the Moon’, NASA Ames Research Center. (https://www.lpi.usra.edu/decadal/leag/DavidJLoftus.pdf )
• Space Suit Evolution From Custom Tailored To Off-The-Rack (https://spaceflight.nasa.gov/outreach/SignificantIncidentsEVA/assets/space_suit_evolution.pdf)
• Belden, L. et al (1991) ‘Design of Equipment for Lunar Dust Removal’, Austin: Mechanical Engineering Department THE UNIVERSITY OF TEXAS AT AUSTIN (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920010136.pdf)

Tools used:

• Blender
• Adobe Photoshop
• Sony Vegas Pro
• Wolfram Alpha