# Presentation: 245701

## Experiment Title: A Biosensor to Measure Surface Reactivity and Iron Effects of Lunar Dust       

**Contact: Sharmila Bhattacharya, 650-604-1531**

| Experiment Objectives: The objective of the proposed work is to determine the geochemistry of lunar dust with respect to surface reactivity and iron toxicity, using the fruit fly Drosophila as a biosensor. This experiment is suitable for lunar surface studies.
Background:
Nanophase iron is abundant in lunar dust and not present on Earth. Neurons in the brain are highly susceptible  to damage due to iron (neuroferritinopathies). We will use wild type Drosophila along with mutant flies that mimic human neurodegenerative diseases (where iron accumulates in target neurons) to compare the effects of the lunar environment on the sensitized mutant backgrounds and wild type flies. Of interest in this context is not only the effect of high iron content in lunar dust, but also the combined effect with the radiation background. Radiation is known to increase ROS and contributes to further neurodegeneration in the above disease models.
The surface of the Moon is exposed to high-level UV radiation, galactic cosmic rays, protons (solar wind and solar particle events), which are likely to generate a charged surface on lunar dust and impart surface reactivity. This surface reactivity can then generate

 | reactive oxygen species (ROS) in biological systems causing cell and tissue damage.
Specific Aims:
1) Assess the neurodegenerative effects of regolith iron and counteract effects with iron chelators. Use well characterized Drosophila mutants that mimic human neurodegenerative diseases as sensitized background to measure the effects of iron in lunar dust. Iron accumulates in target neurons in these disease conditions and increases severity of neurodegenerative effects and decreased lifespan. Neurodegenerative effects will be detected in flies by following behavioral alterations and lifespan. These parameters are easily measurable in space using short video clips and no sample return is required.
2) Determine the toxic effects of reactive oxygen species (ROS) generated by lunar dust by using well-characterized Drosophila mutants with genes encoding potassium channel proteins that act as sensitive in-vivo oxygen sensors. 
These fly lines have an increased metabolism and a decreased life span, are hyperexcitable and show a
locomotor behavior associated with leg shaking. These measurable responses (behavior and lifespan) are exacerbated by ROS and are dose dependent on the amount of ROS present. |
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## Experiment Title: A Biosensor to Measure Surface Reactivity and Iron Effects of Lunar Dust       

**Contact: Sharmila Bhattacharya, 650-604-1531**

| Approach: Overall the operations concept would be to fly a population of fruit flies onto the lunar surface and use short video clips to monitor and measure behavioral movement of the flies periodically. This method has been used extensively in the Bhattacharya lab. Quantification of this data will provide assessment of the degree of reactive oxygen species and iron toxicity effects from the specific fly lines described in Specific Aims 1 and 2.  
AB Roadmap Objective(s) Met:
Goal 5: To understand the environmental limits of life
This proposal seeks to understand the molecular mechanisms that define the physical and chemical limits for life beyond Earth. The surface reactivity and chemical composition of lunar dust can cause a major impact to future long-term human exploration and the setting up of lunar and Martian surface laboratories. This in-situ study of the effects of  lunar dust using a simple organism as a biosensor will help provide preliminary information that can then guide future plans relating to exploration. 
Significance:
(1) Currently there is no repository of lunar regolith | samples that have not been altered to some extent. This experiment can be conducted in-situ on the lunar surface and thus obviates the need to use curated dust samples and increases confidence in the results relating to the biological effects of dust reactivity. (2) An additional advantage of this in-situ study conducted on the lunar surface will be that it will test the combined effect of an environment with elevated levels of radiation, partial gravity as well as dust toxicity. Such an environment would be impossible to replicate on Earth. This information will be invaluable for future exploration plans.
Instrument & TRL: 
The Genesat hardware can be used to sustain this experiment. This is a high TRL instrument with flight heritage (TRL 8). The imaging system is at a TRL of 5. The fruit fly model has flown successfully and reproduced (Bhattacharya et al, STS 121, July 2006), TRL 8. Modifications that will be needed will relate to dust sample collection on the lunar surface, this is at a lower TRL.
Upon discussions with J. Hines and his Genesat team the project is feasible with existing capabilities and that the group has the personnel and knowledge to accommodate the future needs of the project.  

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## Experiment Title: A Biosensor to Measure Surface Reactivity and Iron Effects of Lunar Dust       

**Contact: Sharmila Bhattacharya, 650-604-1531**

| Instrument & TRL (cont): 
A thorough analysis of proposed and proven methods of dust collection will evaluate the suitability of approaches ranging from the system used by the Viking Mars Landers some 30 years ago, to recently proposed approaches from McKay, Zent, Quinn, and Grunthaner for autonomous mini-auger-based sampling of martian dust for chemical analysis.  The unique properties of the lunar dust, including exceptionally sharp particles due to the absence of weathering, and a total absence of surface hydration with resultant high propensity to retain electrostatic surface charge, will be taken into account by
the Genesat engineering team in devising creative conceptual solutions that are small, light-weight, and well matched to minor modifications of the GeneBox/GeneSat hardware.  Overall, we estimate a “FlySat” version of the GeneSat hardware, including dust sampling system, fly life support, measurement, and full power/communications autonomy, would weigh ~7 kg (or ~8.5 kg if the capability to survive lunar night for some time period were to be included). | Measurement Parameters:
Intermittent short video clips.  Experiment can be run over a period of a week or a few weeks.
Environmental Parameters:
Maintain between 15-250C +/- 0.30C
(Temp range already proven possible for Genesat experiments, In fact power can be conserved since high 370C temperature not desired.)
Target Mission/Platform:
-Nanosatellite or microsatellite Platform
-Payload mass 7-8.5 kgs
-Lunar surface mission
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