8. Effect of Dust on Surface Systems

2005: IVA-1A
2010: 3
Priority: Low

(2010 Version)

3. Investigation. Characterize the particulates that could be transported to hardware and infrastructure through the air (including both natural aeolian dust and other materials that could be raised from the martian regolith by ground operations), and that could affect engineering performance and in situ lifetime. Analytic fidelity sufficient to establish credible engineering simulation labs and/or performance prediction/design codes on Earth is required.

Mars is a dry, dusty place. Because of past experience with surface operations on the Moon, it is expected that it would be difficult/impossible to prevent dust from getting into different parts of the landed system. On the Moon, there were three primary anthropogenic dust raising mechanisms (in order of increasing importance): astronaut walking, rover wheels spinning up dust, and landing and take-off of spacecraft. On Mars, we would additionally face winds, which are capable or raising and transporting dust.

We need to understand the potential impacts of dust on the surface system. There are at least three potential deleterious effects that need to be understood: 1). Effects of dust on seals (especially seals that need to be opened and then re-established), 2). Effect of dust on the electrical properties the surfaces on which it accumulates (for example, the effect of dust on circuit boards), and 3). The corrosive chemical effects of martian dust on different kinds of materials. Note that for the purpose of this investigation, we distinguish the effects of direct effects of martian dust on human beings (Investigation #2C above) from the effect of dust on the engineering system that keeps the humans on Mars alive and productive. Significant data about dust properties, dust accumulation rates, and effects on mechanical surface systems on Mars have been obtained from MER (Opportunity and Spirit) and Phoenix, thus the impact of additional measurements of these properties are now ranked lower than in previous versions of this document. However, additional measurements of these properties at other sites would help to understand the range of conditions expected and may still have an impact of mission design.

An important strategy for pursuing this investigation is to collect enough data about the martian dust to be able to create a large quantity of a martian dust simulant that could be used in engineering laboratories on Earth. These data could be best be collected by analysis of a returned sample.

Measurements
a. A complete analysis of regolith and surface aeolian fines (dust), consisting of shape and size distribution, density, shear strength, ice content and composition, mineralogy, electrical and thermal conductivity, triboelectric and photoemission properties, and chemistry (especially chemistry of relevance to predicting corrosion effects), of samples of regolith from a depth as large as might be affected by human surface operations.
b. Repeat the above measurements at a second site in different geologic terrane. Note this is not seen as a mandatory investigation/measurement.

Source:
MEPAG Goal IV Science Analysis Group (2010). “IV. Goal: Prepare for Human Exploration.”
Proposed replacement text for MEPAG (2008), Mars Scientific Goals, Objectives, Investigations, and Priorities. Submitted 2 August 2010.