San Francisco Chronicle - (Sunday)
Trips would help humans become more self-sufficient
The future of space travel is being grown in petri dishes and studied under microscopes at Bay Area laboratories and by NASA-sponsored university biologists around the country.
That’s because the plants, fungi and bacteria that astronauts bring with them into space will determine the success or failure of human colonization of the moon and trips to Mars, say biologists at NASA’s Ames Research Center in Mountain View.
Long-term journeys will require humans to be almost completely selfsufficient — meaning food, nutrients and even building materials would have to be grown in space. And everything from the carbon dioxide astronauts exhale to the sweat on their brows would have to be recycled.
“As we get to more long-term lunar missions, and especially Mars missions, resupply is very expensive, so recycling becomes paramount,” said John Hogan, chief of bioengineering at NASA Ames, who is researching how to grow nutrients, sugars and other substances from yeast in zero gravity. “The long-term goal is to use chemical engineering to feed our bio-organic systems and to manufacture the vast majority of the products humans will need in space.”
It is necessary, Hogan said, because a Mars mission would have to stock all the oxygen, food, sugars, carbohydrates, nutrients and building materials astronauts would need to survive for two to five years. Freezers are too heavy and powerintensive to carry, so all edibles must be freezedried or grown on board.
UC Berkeley bioengineering Professor Adam Arkin is working with researchers at Stanford University, UC Davis, Utah State University and the University of Florida on solutions. He is the leader of the Center for Utilization of Biological Engineering in Space, or CUBES, which has a five-year NASA grant to determine what plants and organisms can be genetically engineered to function and grow into useful products in deep space.
The group is working on ways to convert the carbon dioxide, nitrogen and water found in Mars’ atmosphere into sugars. If they can accomplish that, the theory goes, they could feed those sugars to micro-organisms that would produce food, drugs and even resins that could be fashioned into tools and other usable objects.
“We have organisms that can take those sugars and make plastics out of them,” Arkin said. “We could literally make things that can be put into a 3-D printer, and the 3-D printer could create everything from tools to bioreactors to tables and chairs, ultimately.”
Arkin plans to sequence the genomes and select the seeds and micro-organisms that grow fastest and most effectively in space after testing them in chambers mimicking Mars’ atmosphere. Future space missions would carry seeds and dried yeast that the astronauts would use to grow food and to build resins, NASA officials said.
The goal, essentially, is to create a self-sustaining biological and ecological loop.
Learning how to survive long-term in space is important because there is frozen water on both the moon and Mars — two-thirds of Mars’ northern hemisphere is believed to be covered by frozen water. With the world population growing and resources becoming scarcer, the future of humanity could depend on exploiting extraterrestrial sources, many astrobiologists say.
In addition to growing food and materials, NASA bioengineers are developing systems to quantify, capture and recycle everything astronauts use, eat and emit, including body fluids. The International Space Station already has systems that capture the carbon dioxide people exhale and recover the oxygen for recirculation.
The plan for long missions is also to collect every trace of moisture from breath, sweat and urine, put it through reverse osmosis and add it to the drinking water supply. Hogan said work is now under way to build systems that would extract the nitrogen, carbon and oxygen from feces and reuse it. The remainder would be dried, heated and turned into a solid that could be used to build radiation protection shields, he said.
One of the things NASA scientists hope to figure out is how long bacteria, plants and fungi can survive in deep space and how they are affected by cosmic rays. The CUBES program will include those calculations in its model.
Some of Arkin’s experiments are likely to be employed on the moon orbiter known as Gateway scheduled to launch in 2024. If all goes as planned, a whole slew of space-adapted organisms will be ready to go by 2033, the favored launch window for a manned mission to Mars.
“This is just the beginning,” Hogan said. “It’s a humanities process decades in the making that will be useful on Earth in the coming decades, but will definitely be needed on Mars.”
Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@ sfchronicle.com Twitter: @pfimrite