When they ran out of oxygen, the scientists living in Biosphere 2 were able to pop open a door and take a breath of fresh air. For astronauts living on Mars or the Moon, things won't be so convenient. Biosphere 2, after all, was located in a greenhouse-like structure in the Arizona desert. NASAs effort at creating a sealed, self-sustaining environment must be successful the first time.
"There was mostly faith behind Biosphere 2, with little research," says Purdue University Professor Cary Mitchell. "If [NASA] just sent people to Mars on a wing and a prayer like that, and the crew died, how long do you think it would be before Congress gave them money to do anything again?"
Mitchell will resume directorship of the NASA Specialized Center of Research and Training for Advanced Life Support (ALS NSCORT) on October 1. He was also the director of the first ALS NSCORT created in 1990, before it was moved to Rutgers University in New Jersey in 1995.
The focus of the Center is to study how to create a self-sustaining habitat for space colonies or long-term missions to the Moon or Mars. Missions where it would be too far or too expensive to send supplies such as food, air and water. "The whole deal is learning how to become independent and autonomous of Earth, where if you cant live off the land, you take resources with you and recycle them, like living in a bubble," Mitchell says.
These bubbles, like Biosphere 2, will simulate the interdependent processes on Earth (Biosphere 1) that sustain the natural environment. However, the system will be simplified to include only the processes essential for life, such as growing food to eat and creating oxygen to breathe. Because some of these mechanisms take place over along time, they will be speeded up with the help of microbes or some other technology. "They will be driven by human effort by brute force, if you will," Mitchell says, and that is what the Center will study.
NASA encouraged universities applying for the grant to include a minority university as a partner. Purdue chose both Alabama A&M and Howard Universities because of existing research collaborations.
Funding for the NSCORT, worth $10 million over five years, will be split between four main areas. Half will be dedicated to researching waste management. Instead of constructing septic tanks or waste treatment facilities like we have here on Earth, Mitchell and his colleagues will try to devise a way to "turn solid, liquid and gaseous waste over back into safe, renewable resources that can be used again without creating pollutants, contaminants or toxicants," he says.
Katherine Banks, NSCORTs Associate Director, works in this area. She and her colleague Al Heber are devising a way to use microbes to simultaneously clean the air and recycle "gray water," the waste water left over from bathing and washing dishes. They are examining "attached growth system where the microbes are attached to some surface," Bank says.
A type of attached growth system is already used to remove contaminants from waste water at treatment plants, Banks says, and these "biotrickling filters" have also been used in agricultural settings, such as livestock feeding facilities, to clean the air. "But nobody has thought about doing it simultaneously because there isnt a good use for that on Earth; we just dont have the closed system like you would on Mars."
However, Banks does see some Earth-side applications. "I feel like this could be used in other situations where you could have a closed habitat, such as research missions to Antarctica, or situations where you dont want to lose any of your air because of loss of heat, or something like that."
Another twenty percent of the Centers funding will be dedicated to food technology, the area of Mitchells research. One of the problems future space colonists will face is growing enough food to eat without using up all of the resources to do it. A mostly vegetarian diet, with some fish, is the most feasible to maintain in a space colony because it would require the least amount of energy input while still producing a well-balanced diet. Potential crops include legumes, such as cowpeas and soybeans, and wheat and rice.
To further maximize crop production using the least amount of energy, Mitchell has designed what he calls "intra-canopy lighting." This system uses colored light emitting diodes (LEDs) "arranged on plastic strips like pathlights in movie theatres," he explains. The color of the LED strips matches the peak absorption spectrum of the plants so there is little wasted energy. The strips are then hung "like lightsicles" and the plants grow up around them.
Other researchers who use LEDs have mostly used a single overhead light source, requiring the canopy, or top of the plants, to do most of the photosynthesis, Mitchell says. Initial results are positive, resulting in half the productivity while using only 10 percent the energy. "And thats not even with LEDs," Mitchell says. "Thats with little fluorescent kitchen lamps."
Another ten percent of the Center's funding will be invested in outreach to children and the general public. The final twenty percent of the grant will be dedicated to systems analysis. This group takes the information from all of the separate research areas and integrates them into a model to not only better understand what is going on in the different processes, but also to create a sustainable closed system in a computer. "You've got to do this before you spend millions and millions of dollars to test these things in closed system chambers," Mitchell says.
The research conducted by the NSCORTs will eventually go towards building a test colony on Earth to simulate what would be erected on Mars or the Moon, not unlike Biosphere 2. "If anything happens or goes wrong," Mitchell says, "theyll just open the doors and the people will walk out."
When the time comes, Banks has a suggestion as to who should be sent to colonize Mars and the Moon. "The greatest sign that you have confidence in your system is to use it yourself," Banks says. "So I think all of the designers should be the guinea pigs!"
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