Building a Mars Base with Bacteriahttps://phys.org/news/2019-11-mars-base-bacteria.htmlHow do you make a base on Mars? ... Benjamin Lehner, a Ph.D. student at Delft University of Technology with a background in both nanotechnology and biology, has now come up with a plan that does not involve any human beings in the first couple of years. His plan also eliminates the need to send heavy materials to Mars. In his dissertation, Lehner proposes the use of unmanned capsules containing three components: a rover, a bioreactor and a 3-D printer.
The rover is not much more than a shovel on wheels. During the day, it scoops up the iron-rich Martian soil (called regolith) and brings it to the bioreactor. This reactor is filled with bacteria of the
Shewanella oneidensis species. "In its natural form, we can't use much of the iron in the Martian soil," explains Lehner. "But
S. oneidensis has the ability to turn part of the soil into magnetite, a magnetic oxide of iron."
After the bacteria have done their work, the magnetite can be extracted with magnets. Using a technique called Lithography-based Ceramic Manufacturing (LCM), the 3-D printer then converts the raw material into screws, nuts, iron plates and other objects—everything that future settlers need to build a Martian base.
Some major advantages of bacteria are that they are self-reproducing, easy and cheap to transport and that they can withstand high amounts of radiation. In Lehner's plan, micro-algae feed the bacteria. These algae convert sunlight and CO2 from the Martian atmosphere into nutrients and oxygen. They also produce residual waste, which will be an important resource for the first settlers of Mars since it can be used as compost. The biomining reactor itself also produces such organic waste.
... Lehner and his team have calculated how much iron one unmanned capsule with a 1400 liter reactor could produce: about 350 kilograms per year. "After 3.3 years, it would produce more iron than can fit inside the capsule," he says. "By sending several of these unmanned modules to Mars, we can produce a good amount of iron in a few years' time."
... ESA and NASA have already indicated that they would like to develop Lehners ideas further. https://repository.tudelft.nl/islandora/object/uuid:acd7102b-339b-45b5-972e-fe3a2ad9c52e?collection=research