---

Brent Bos:

The two research topics I brought to MDRS were a dust contamination study and a human factors study.

The motivation for initiating the dust study is the potential hazard Martian dust poses to a human Mars crew. Next to the high radiation environment and the low gravity field on Mars, dust is probably the next biggest danger a manned mission might face. The seriousness depends on the specific nature of Martian dust and soil, which we are still trying to understand through robotic missions. But at a minimum the dust will cause premature failures in mechanical, electrical and thermal systems. And at its most serious, it could cause dehabilitating illness and jeopardize the health of the crew.

Most mission planners believe the dust threat can be mitigated with proper spacecraft and system hardware engineering. The goal of the study at MDRS was to help us understand how big of an engineering problem we might be facing.

The analogue dust study measured and characterized the amount of soil and dust contamination brought into the Habitat through EVA activity. The amount of dust, in terms of mass, and the sizes and shape of the contaminating dust particles were measured for 12 out of the 14 EVA's. EVA's #3 and #12 were not studied due to the EVA team's significant contact with water. EVA characteristics such as type (pedestrian, ATV or pressurized rover), distance traveled, work engaged and number of members were recorded to study their affect on the amount of contamination.

The human factors study quantified the performance of the crew throughout the simulation. There were several areas of interest for this research. But one of the key questions being investigated was the affect EVA frequency has on a crewmember's well-being.

Each morning crewmembers were asked to fill out a one page questionnaire describing their mood, level of alertness, stress level, crew compatibility, amount of sleep, etc. And each evening the crew completed a computer based test to measure their alertness and visual-tactile coordination. A large amount of data was collected but none has yet been analyzed. The crew was very cooperative in completing this study.

---

Petra Rettberg:

Biological UV Dosimetry: On Mars the UV climate is quite different than on Earth, because the thin atmosphere of Mars consisting mainly of carbon dioxide is not able to absorb the short wavelengths of UV radiation as the terrestrian atmosphere does. Therefore energy-rich UV radiation (wavelengths down to 200 nm) can reach the surface of Mars. The exact measurements of the biological effectiveness of that UV radiation on biological processes in terrestrial organisms is of importance for bioregenerative life support systems and for the future development of agricultural plants for Mars.

The assessment of the influence of environmental UV radiation on critical biological processes requires monitoring systems that weight the spectral irradiance according to the biological responses under consideration. The need for a biological weighting of solar UV irradiance derives from the highly wavelength-dependent sensitivity, expressed as the so-called action spectrum, of biological systems in the UV range of the electromagnetic spectrum. Biological UV dosimeters, that weight directly the incident UV components of sunlight in relation to the effectiveness of the different wavelengths and the interactions between them, can complement weighted physical UV measurements. Here at the MDRS we have used a well-characterized biological UV dosimeter, the DLR-Biofilm. It consists of spores of the ubiquitous apathogenic bacterium B. subtilis as UV sensor. We have performed different biological UV dosimetry experiments:

• Personal UV dosimetry of crew members during EVAs compared to parallel stationary biological measurements of ambient UV radiation, to get information about the influence of movements and the type of activities on the individual UV doses. These measurements have been performed during each EVA up to now. All in all we have exposed a total of 50 UV dosimeters for personal UV dosimetry and for the parallel ambient measurements.
  
  
• Measurement of the biological effective UV doses beneath layers of natural soil of different thickness compared to parallel samples with the Martian soil analogue JSC Mars-1 to get information about the shielding capacity of soil and dust, e.g. on Mars. We finished one short exposure (2 days) and one long exposure (9 days).
  
  
• Measurement of diurnal UV profiles with larger DLR-Biofilms than those used for personal UV dosimetry that have 20 measurement areas on each film to see changes in the solar irradiance during the day. We measured a total of 3 diurnal UV profiles, with small interruptions in two of them due to a short period of rain.
  
  
• In addition the erythemally weighted UV radiation was measured in the first week with an electronic UV dosimeter (X20001, Gigahertz-Optik, Germany) for a direct comparison with the biological UV data. The time-resolved data have been down-loaded every evening.

The analysis of the biological UV dosimeters will be done in our laboratory. Previously unirradiated areas on each DLR-Biofilm will be exposed to different doses of a standard UV calibration source (mercury low pressure lamp, main emission line at 254 nm). Then each biofilm will be incubated in nutrient medium at a suitable temperature for about 5 hours. During this incubation the bacterial spores that are not or only slightly damaged by the applied UV radiation will germinate and the vegetative bacteria will multiply in the biofilm. The amount of biomass formed during this process will be stained after a fixation step. The analysis of the calibrated, and processed biofilms, where the different measurement, calibration and dark control areas show a different degree of staining, will be done by computer-aided image analysis. From the individual calibration curve of each film the biologically effective UV doses will be calculated for each measurement field on the dosimeter film. The results of this UV measurement campaign with the biological UV dosimeter DLR-Biofilm will be available in the next few weeks.

---

Dave Scott:

My scientific goals were largely to support, augment, aid and back up other people's work. As a last minute addition to the crew, I had little time to create my own research goals and so asked to see where I could be helpful. I wrapped up a stratigraphy section up in Salt Wash, done by Rocky Persaud from Crew 14. I made arrangements for a collaboration with the USGS for some dust research - if I put up USGS standard dust traps and send them the dust, then they do what they can to analyze what we collect. Hopefully this will help Brent's work with dust studies, which I did some research for, mainly to predict the general composition of the dust contamination. My geology experience was also useful for Mark's research (see below), where I provided 3 models for methane production and scouted for the most suitable sites. I also helped Elia and Simone find some of their sites for halophile organisms.

---

Elia Husiatynski & Simone Kosol:

We came to MDRS to work with halophile (salt loving) archeae. We want to work with halophiles because they have a better chance than non-halotolerant organisms to survive on Mars, due to the broader temperature range high salt concentrations offer for liquid water.

We decided to do two different experiments: the first is exposure studies with three different strains of halophiles dried in salt crystals together with one of these strains in liquid culture. The second experiment is to take some samples from interesting sites. "interesting" means with salt in the soil or water to see if these samples contain halophiles.

The salt crystals containing archeae (Halococcus salifodinae, Halococcus dombrowskii and Halobacterium sp. NRC-1) have been exposed from 28.4.2003 to 10.5.2003 on five different sites. We will process the samples at the University of Salzburg to get any data of changes or differences in the survival rate of these archeae.

The liquid cultures (halobacterium sp. NRC-1) were also exposed on five different sites but for a different exposure length. The duration of the exposure varies between one day and 12 days. These samples will also be analyzed at the University of Salzburg.

We took 30 samples from different locations in this area. Our crew geologist Dave was very helpful at finding sites with salt deposits (thank you, Dave; and thank you Shannon Rupert for support with selection of sample sites). We will probably not analyze all of these samples, because we have only the resources to study the most promising ones. The samples were taken between 28.4. and 10.5.2003. These samples are taken from the surface (max. 10 cm depth) and have obviously different salt concentrations. There is also one liquid sample taken from Muddy Creek, a river with a lot of salt deposits on the river banks. At the University of Salzburg we will try to find halophiles in these samples, when solving the soil samples and trying to cultivate any halophiles in and on different media.

We expect to find halophiles in some of the soil samples and we think we will have some interesting results of our exposure studies.

---

Mark Moran:

I had two main research topics: 1.) a sample of methane gas vapor extractions from simulated Mars regolith for the purpose of detecting indigenous anaerobic life; and 2.) an organic water contaminant detection instrument getting its first calibration as a tool for preventing contamination, or recognizing contamination when it occurs. As of this writing, I have one last EVA attempt to carry out drillings with gas vapor extractions. I also expect to carry out some final water calibrations today.

In both cases I have made substantial progress toward the respective scientific goal, and in both cases there have been challenges. Brent Bos of NASA has helped me to stay on task and progressing toward my goals. In the case of gas vapor drilling, we experienced a rain shower during our second to last EVA after our first hole and some of the crew thought that further drilling should be discontinued. Preferring the good will of the crew, I consented to abort the EVA. Had I, as a last-minute transfer from crew 17 to crew 18, felt greater clout under the circumstances, I certainly would have insisted we do one more drilling given that the one drilling we did accomplish on that day was superior to any previous attempt.

When scouting on ATV for sites, one should bear in mind that there are issues of experience, on the one hand, and independently there are also issues of risk-taking vs. risk-aversion.

Throughout several EVAs the level-headedness of Brent Bos and the able assistance of our geologist Dave Scott were indispensable to me and a factor that greatly contributed to the successes that we enjoyed.

For the water organics detection experiments using Dr. Starikov's device, a single sample was sufficient to bring out inadequacies for in-sim (i.e., EVA) conditions. Variations in sunlight would ruin the readings, by contrast with indoor (IVA) readings which were consistent and worked well. Dr. Petra Rettberg has been quite helpful during these measurements.

Both the contamination detection experiment and the drilling experiments will require laboratory analysis. Professor Timothy Kral will analyze the gas contents of the Tedlar bags, and Professor David Starikov will analyze the water contamination. Overall, I would say that the drilling/vapors objectives have been 80% met, and the water organics detection objectives have also been 80% met.