CUSTOMERS & USE CASES

NASA’s International Space Station (ISS) has amazing technology. The water recycling systems (WRS) on board treats water from urine, oral hygiene, hand washing and fuel cells for drinking (and all other uses) by astronauts.

“The water that we generate is much cleaner than anything you’ll ever get out of any tap in the United States,” says Layne Carter. It’s practical too. The WRS saves NASA approximately $400 million per year on re-suppling water to the ISS.

The success of that technology led to applications on earth. In 2006, the first of many ground-based water filtration systems using NASA technology was installed in northern Iraq in the tiny Kurdish village of Kendala, Iraq.

The WRS does have limitations. “One of the main lessons learned [from the WRS] is that reliability is a key technology performance metric.” It “is a key cost driver and is a critical factor in insuring crew safety.” The WRS, a mission critical system, requires maintenance or repair every 90 days. For a typical Mars mission, that could last three years or longer, a limitation that would affect both mission safety and cost.

Water conservation is not an option. “On the [International] space station, people will wash their hands with less than one-tenth the water that people typically use on Earth. Instead of consuming 50 liters to take a shower, which is typical on Earth, denizens of the ISS will use less than 4 liters to bathe.”

“Michael Flynn purposed developing a next generation water filtration system capable of self-repair.” He was inspired by our internal organs. “The human heart, lungs, and digestive system have an expected life greater than 50 years with minimal to no maintenance. This is because biological systems have undergone billions of years of evolutionary improvements.”

This capability to mimic biological systems is called synthetic biology. Synthetic biology is the engineering of genes in bacteria so that the bacteria perform a desirable function. For NASA, that desirable function is in situ resource utilization, which means the regeneration of resources from a combination low cost materials and waste products. “Areas of interest [to NASA] include in situ resource utilization; biomembrane-based filters; bio-based production of materials for advanced manufacturing; biological 3-D printing; bio-mining to obtain minerals from planetary surfaces or spent electronics; production and purification of “on-demand” pharmaceuticals; food production; life support; and tools to address astrobiology questions.”

Michael Flynn knew development was game changing and challenging, as evidenced by Monsi Roman, chief microbiologist for the ECLSS project at MSFC, who said that ECLSS depends on machines — not microbes — because “if a machine breaks, you can fix it.”

Michael Flynn engaged zNano to help with development. zNano and NASA had previously successfully collaborated before to evaluate bioinspired forward osmosis membranes comprised of lipid bilayer resulting in a publication a year earlier.

The goals were ambitious:

Demonstration of a functional bio-membrane that can be used for wastewater treatment.

Demonstration of the ability of the membrane to recover from fouling or oxidative damage.

Demonstration the membrane has performance characteristics comparable with the current SOA. *

Together, NASA and zNANO developed SBM technology. SBM technology uses the bodies natural soap, fatty acids or FAs, to protect the membrane. In [an SMB] configuration the FAs on the surface of the membrane are regenerated by using synthetic biology. In this case genetically engineered cyanobacteria. “We have determined though testing that most of the macronutrients needed by cyanobacteria can be supplied by urine in the feed stream.“ These FAs are able to permeate through the lipid membrane from the OA into the feed side of the membrane. On the feed side, the solubility of the FAs drop and they precipitate out on the surface of the membrane producing a sacrificial coating.

SBM technology is being developed to integrate into a batch FO/RO system. The FO/RO system has a recirculated feed is across the FO membrane and on the other side of the FO membrane a salt solution with a higher osmotic potential which causes water flux across the membrane. The osmotic agent is then reconstituted using a batch reverse osmosis system. A synthetic biology bioreactor is integrated into the osmotic agent loop to provide a source of fatty acids to protect the FO membranes.

The results of the program were presented in an impressive trade study evaluating an “equivalent system mass (ESM) evaluation of the Synthetic Biological Membrane (SBM) compared to the current International Space Station (ISS) state of the art as defined by the Urine Processor Assembly (UPA) technology.” “Results of this trade study indicate that the SBM System has 80% lower ESM than the UPA when combined with a forward osmosis/reverse osmosis (FO/RO) water treatment system. In addition, the ESM of the FO/RO is 50% lower when used with the SBM technology. “ “Differences between biological fatty acid (FA) synthesis and ground resupply of FA’s is minimal for a 182 day mission studied but increases with mission duration.“

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