Charles Buhler

Controlled particle removal from surfaces by electrodynamic methods for terrestrial, lunar, and Martian environmental conditions

An Electrodynamic Dust Shield to remove already deposited micron-size particles from surfaces and to prevent the accumulation of such particles on surfaces has been developed. In addition to terrestrial application, our NASA laboratory is adapting this technology for the dusty and harsh environments of the Moon and Mars. The Apollo missions to the moon showed that lunar dust can hamper astronaut surface activities due to its ability to cling to most surfaces. NASAs Mars exploration landers and rovers have also shown that the problem is equally hard if not harder on Mars. In this paper, we show that an appropriate design can prevent the electrostatic breakdown at the low Martian atmospheric pressures. We are also able to show that uncharged dust can be lifted and removed from surfaces under simulated Martian environmental conditions. This technology has many potential benefits for removing dust from visors, viewports and many other surfaces as well as from solar arrays. We have also been able to develop a version of the electrodynamic dust shield working under hard vacuum conditions. This version should work well on the moon. We present data on the design and optimization of both types of dust shields as well substantial data on the clearing factors for transparent dust shields designed to protect solar panels for Martian exploration.

Measuring the Size and Charge of Dust Particles in the Martian Atmosphere

Publisher Summary This chapter presents the preliminary results of particle size distributions and charge-to-mass distributions of Martian simulants using a miniaturized prototype version of a commercially-available instrument originally developed by one of the authors at the University of Arkansas at Little Rock (UALR). This prototype, recently completed by UALR and the Kennedy Space Center, may be used to characterize the size and charge of dust particles suspended in the Martian atmosphere. The chapter discusses the possible applications of this instrument for lunar missions. Dust is airlifted into the atmosphere by frequent Martian dust devils as well as by the more infrequent regional and planet-wide dust storms. This phenomenon may compromise the duration of robotic and even future human missions to Mars, as it poses a serious problem for solar arrays, spacecraft, spacesuits, and equipment. In spite of several successful landing missions to the planet, very little is known about the dust itself. It is believed to be comprised of particles with diameters less than 50 micrometers. In the presence of low moisture condition, this dust is also likely to be statically charged either triboelectrically, as particles collide with each other and the surface and/or photoelectrically, by the incident UV irradiation. The presence of electrostatic charge on the dust particles has important consequences not only in terms of understanding the atmospheric phenomena on Mars but also the methods for controlling dust for future planetary missions.