Microbial induced calcite precipitation can consolidate martian and lunar regolith simulants

We demonstrate that Microbial Induced Calcite Precipitation (MICP) can be utilized for creation of consolidates of Martian Simulant Soil (MSS) and Lunar Simulant Soil (LSS) in the form of a 'brick'. A urease producer bacteria, Sporosarcina pasteurii, was used to induce the MICP process for the both simulant soils. An admixture of guar gum as an organic polymer and NiCl2, as bio- catalyst to enhance urease activity, was introduced to increase the compressive strength of the biologically grown bricks. A casting method was utilized for a slurry consisting of the appropriate simulant soil and microbe; the slurry over a few days consolidated in the form of a 'brick' of the desired shape. In case of MSS, maximum strength of 3.3 MPa was obtained with 10mM NiCl2 and 1% guar gum supplementation whereas in case of LSS maximum strength of 5.65 MPa was obtained with 1% guar gum supplementation and 10mM NiCl2. MICP mediated consolidation of the simulant soil was confirmed with field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Our work demonstrates a biological approach with an explicit casting method towards manufacturing of consolidated structures using extra-terrestrial regolith simulant; this is a promising route for in situ development of structural elements on the extra-terrestrial habitats.

Lunar Science, Resources and Innovation at Field Simulations

<p>Hawai`i Island has had a pivotal role in human Lunar Exploration by virtue of its high-fidelity science and technical field sites.  The geologic and historically recent volcanic landscape along with the geochemical simularity of Hawaiian basalts with Lunar basalts have made Hawaii a prime location for field test simulations.   This presentation will briefly highlight the legacy Apollo astronaut geology training. The  post-Shuttle <em>In-Situ</em> Resource Utilization (ISRU) field tests on equipment &  techniques for lunar oxygen production will be covered along with mission simulations for NASA’s RESOLVE and VIPER lunar polar missions.  Google Lunar X-Prize (GLXP) field trials have also occurred.  Finally educational aspects with University level robotic mining competitions (Lunabotics/RMC/PRISM) will be shown.</p> <p>            The geo-technical properties of the tephra (basalt sand) at the field site(s) will be explored, and shown to provide a good lunar simulant for laboratory use and experimentation. Samples are still currently available for researchers.</p>

Bacterial Growth Induced Biocementation Technology, ‘Space-Brick’ - A Proposal for Experiment at Microgravity and Planetary Environments

We present results of our investigation of microbial induced calcite precipitation for manufacturing ‘space bricks’ and a proposal for study of this activity in low-earth orbit (LEO). Sporosarcina pasteurii, a urease producing bacterial strain was used to consolidate lunar simulant soil (LSS) in the form of a ‘brick’ with non-trivial strength properties. Potential of a naturally occurring polymer namely, guar gum, as an additive was investigated for enhancement in compressive strength of bio-consolidated samples. Experimental results of bio-brick exhibited an approximate 10-fold increase in compressive strength with guar gum supplementation in soil. We present results of microstructural analysis of the ‘space bricks’ and also propose a payload design for related experiments in LEO.