Friday, February 17, 2017
Exhibit Hall (Hynes Convention Center)
Hunter Bishop, Brevard High School, Brevard, NC
James Thompson, Brevard High School, Brevard, NC
Solid carbon dioxide, or dry ice, is plentiful on the surface of Mars, accumulating in vast deposits near the poles and undergoing a cycle comparable to water’s on Earth. Because such quantities are available, a method of deriving energy from dry ice could have significant implications for powering human colonization of Mars. A particularly desirable property of dry ice is its ability to sublimate, or change directly from a solid to a gas at only -78℃. That sublimation within a closed container allows for enormous pressures to be reached by relatively small quantities of dry ice and small amounts of heat. Pressure engines have been used on Earth for centuries, and though conventional pressure engines are driven by compressed air or steam, carbon dioxide might be an adequate substitute. Components of a rudimentary pressure engine were assembled. An Arksen bead seater, chosen for its large valve, was used as the pressure vessel through which dry ice could be inserted quickly. An air hose connected a valve on the bead seater to an angle die grinder, which spun a DC motor, generating power. Current was measured by a multimeter wired in series, while voltage was measured by a Vernier LabQuest wired in parallel, and a 2.5 Volt, 200 mA light bulb acted as a resistor. Electricity was produced in amounts comparable to tests with compressed air, causing the light bulb to shine brightly, and, showing that, with further development, a dry ice pressure engine could be used to generate power on our excursions to the Red Planet.