L UNAR -M ARTIAN D UST S IMULATION A PPARATUS Tyrel Ellis Jonathon Pierson Matt Merritt

P ROBLEM S TATEMENT Develop, construct and test a method for production of electrically charged particles to be used for the NASA dust experiments.

B ACKGROUND I NFORMATION Electrostatically charged particles pose significant threat to human health and machine reliability during Martian/Lunar exploration and habitation. Collision of particles with space suits, vehicles and machinery can transfer charge leading to rapid adhesion. The proposed project will explore concepts of an active surface with integrated dust sensors and dust detachment and removal actuators to provide mitigation of dust particles with minimal energy expenditures.

P ARTICLE S PECIFICATIONS Ranges from 0.01 to 100 microns in diameter.

A TMOSPHERE C ONDITIONS Martian Atmosphere: surface level pressure = 600Pa Lunar Atmosphere:One trillionth the density of Earth’s atmosphere

P ROPOSED S OLUTION : O VERVIEW We will be charging the particles using the triboelectric effect. We will be determining the charge with the ESPART analyzer The particles will be delivered by a CO2 propulsion system

Triboeletric Charger ESPART Sensor Delivery System UVM Test Chamber S YSTEM D IAGRAM

C HARGING Charging will occur through a triboelectric effect caused by tumbling the particles in a tumbler. Possible materials include: Teflon with stainless steel beads Glass Charge-to-mass ratio (Q/m) of JSC-1 Mars stimulant ranged between 6.42 and micro- coulombs per gram (Sharma)

ESPART A NALYZER The Electrical Single Particle Aerodynamic Relaxation Time Analyzer The ESPART analyzer uses the principle of Stokes’ Law and Laser Doppler Effect in determining the particle size and charge. As a particle travels through air it experiences a drag force which is proportional to the diameter of the particle, given by Stokes’ Law. Charge also effects its diameter given.

ESPART S ENSOR : H OW IT W ORKS The MiniLDV emits two laser beams that when a particle travels through the intersection of the beams, they are read by the receiving lens and a sinusoidal wave is formed. The larger the charge of the particle the larger its signature is.

CO2 D ELIVERY We will use compressed CO2 to deliver the charged particles into the UVM test chamber CO2 is used to: Keep humidity low Simulate the Martian environment Keep the vacuum stable

U NKNOWN F UTURE C IRCUMSTANCES We may need to put the entire system in a vacuum in order to keep the particles charged once the charge is attained The ESPART analyzer is large, so we may need a separate vacuum chamber to house our device

Q UESTIONS ?