I've done some study on lunar regolith, during the Concept Exploration and Refinement. I participated on the Boeing study, and in most phases of the operation, dust becomes a problem. For example, the transition from extravehicular to internal activity, during maintenance operations, etc. The effects of regolith are not confined to humans or rolling vehicles, either. The films of ascent stage operations from Apollo show the potential for damage from thrown regolith, and the plan for building up locations with mulitiple landings mandate some mitigating strategy in the system design.

Pressurized spaces are probably the easiest to handle. In my grandmother's farmhouse in Tennessee, there was a weather room where you entered the house if you were coming from the direction of the fields and buildings. That room is where you removed your boots, gloves, coats, and changed into house clothes. The room was pretty chilly, had an unfinished floor, and was easily cleaned with a mop and broom. The problem is very similar, and so is the solution. A vestibule, probably a two stage vestibule, with sticky mats similar to a clean room provides an environment to transition. The outer room is where you drop your outer clothing, the inner one is where you don the inside clothes. An electrostatic or combination electrostatic/mechanical separator in the outer room could remove the tracked in regolith, after the crew has entered the inner vestibule. The inner vestibule could have cleaning materials to remove the last of the regolith picked up on the skin (probable during stage one of transition). These vestibules could be inflatable, movable, cleanable and replaceable.

Outside is another problem. Regolith shrapnel from nearby launches ( the standoff distance in 1/6 g is considerably further than in 1 g) could present danger to humans and equipment. One mitigation is to have a separate area for blasting off the surface, behind berms of regolith or man-made panels for deflecting and channeling debris. This should sound familiar to military air folks. We do the same thing at temporary and permanent airfields, to protect from FOD. In the lunar case, this means that there also needs to be some capability of moving hardware in and out of this zone, which implies a surface transportation capability, or having man-portable panels that can be erected around the launching or landing vehicle, and some way of stably erecting them for protection. Another implied need is material handling equipment. Outside maintenance operations pose other problems. By opening an interface, you expose that interface to dust. Using tools introduces dust. While thankfully not having wind to deal with, unfortunately, you have the electrostatic charge of the regolith to move it around, and the potential differences of gloved hands and powered or unpowered equipment to create opposing charges. Design of removable components and parts only partially addresses the problem, isolating the new parts and components is another story, another design challenge. Hydraulics and electrical equpment are two especially susceptible categories, but mechanical interfaces are also problematic. You can limit mechanical problems by increasing clearances, loosely fitting them to allow for regolith build up and break down, but that usually means more mass in stronger, more durable interfaces.

I suggested that revisiting an Apollo landing site might be useful as a study to find out the effects of regolith over time. RTG's, moon rovers, batteries, mechanical connectors...there is a wealth of hardware that's been in the open for many years, all exposed to thrown regolith, heat, cold, and radiation. Our choices back in the 60's could be evaluated against the current design trade space, either using a robotic collector and test hardware early in Constellation, or during the lunar sortie stage of the exploration. That idea had already been posed as a public outreach event, but was discarded as unnecessary. I think it probably has value as both.

A Space Loggie