Algae Might be the Ingredient Needed to Make Long-Term Space Travel Possible

A new field of research believes algae might be the ingredient needed to make long-term space travel possible. Emily Matula, who is studying at the University of Colorado Boulder, stated that her research team thinks one system of algae could be used to solve almost all of the metabolic needs of future astronauts

Matula’s Ph.D. is centered around ways of removing waste heat via systems much like those aboard the International Space Station (ISS). The interior of the ISS has an array of coils filled with water so that when the astronauts inside the craft release heat, the water heats up. When the water in the coils hits a specific temperature, it is then pumped past a cold plate which is connected to the outside of the station. The heat moves from the water to the plate and is expelled from the ISS.

Thus, Matula explained that since there is already a water loop system in place, her concept is to fill the water loops with an algal culture so that two life support system processes would be addressed using one system. Now, Matula is analyzing how the algae would react to being inside those systems, which has fluctuating temperatures. The goal is to figure out if they are still able to use up carbon dioxide and generate oxygen at the necessary rates.

Although the findings have not been published as of now, so far the process has the potential to reduce the cost of launched mass, power, and volume. This experiment also seems viable for air revitalization as it could remove carbon dioxide and generate oxygen, helping astronauts breathe.

We know for sure that it works on Earth. Experts estimate that the amount of oxygen produced by algae is between 50 and 80%, but that doesn’t mean it would produce oxygen at the same rate in space.

In 1961, Russia performed an experiment where a man was kept in a 4.5 cubic meter room for 30 days, using only algae to turn his carbon dioxide into oxygen, as reported in the book titled Environmental Biotechnology.

Only three days into the experiment the dangerous levels of carbon monoxide stabilized and, 12 days later, the methane given off by his own body was also stable. However, as Matula explained it’s hard to get her hands on the data from this experiment.

Of course, the most crucial step is to determine if algae can be grown in space. In 2018, from February to August, NASA’s Space Algae experiment aboard the ISSlooked at the way algae grows in a zero-g environment.

Mark Settles, of the University of Florida and the chief investigator on the project stated that they were looking to find a cheap way to grow algae in liquid cultures in space because algae grow fastest in liquids. However, there are many challenges for handling liquids without gravity.

During their tests, they also looked at whether certain genetic variations would algae to survive better in space. Within the six month experiment, they created algae mutations by exposing it to UV light, then growing each different strain for 40 generations. Settles explained that they were trying to determine what genes are vital for algae to grow well aboard the Space Station. They are presently characterizing if they got significantly different strains in comparison to conducting the same experiment on Earth.

One of the most promising possibilities is to use algae for food since many forms of algae are edible. Kevin Tyre, a payload analyst at the International Space Station and the manager of NASA’s Space Algae experiment, stated that when it comes to food applications, it’s more than probable that it would be used as a nutritional supplement instead of a dietary staple.

Algae are also promising for helping shield future astronauts against radiation. Out in space, astronauts are inundated by highly energetic particles called cosmic radiation. It’s imperative to find something capable of blocking that radiation if we want to survive long-duration space missions.

For now, many layers of various materials work to shield astronauts from this radiation aboard the ISS.

Therefore, Settles explained if algae are grown in liquid culture, and the reactors are placed on the outside of the spaceship, they could be used to help block the radiation too. However, more research is needed to figure out which strains of algae could withstand cosmic radiation.

Another great potential use for algae is waste removal. If human waste can be used as a source of food for the algae, it will recycle nutrients such as phosphorus and nitrogen into something that could potentially be eaten by the crew. This could also work on our planet, too where countries with limited resources like India are interested in using algae for industrial or human waste removal, according to Matula.

Lastly, the experiment tested whether algae could be used to produce oils for biodiesel or high-value carotenoids, such as vitamin A. Settles stated that oil and carotenoids are both generated at higher levels when the environment stresses the cells. For instance, if algae are starved of nitrogen or sulfur, they make energy-dense oils. So the team is now testing their algae space samples to determine if growing algae in space generate more oil than producing it here on Earth.

In the future, this could be used to help space manufacturing because the oils generated by algae could be used to make plastics or fuel in space.

Although this experiment looks promising, there could also be possible downfalls to using algae in space. For instance, if the algae’s waste oxygen is not removed fast enough, it will slow the growth of algae. Another possible downfall is contamination from chemicals or bacteria. For example, if the algae are given contaminated waste it has not been treated correctly it could become hazardous for those consuming it. If the astronauts consume substances like caffeine or antibiotics, which are not natural for algae these substances could accumulate in the algae, which might end up being dangerous for humans if they eat them.

However, algae have shown promise in each area of survival requirements including, heat removal, waste removal, air revitalization, water, radiation shielding, and fuel. But combining them all has not yet been done.

Photo credit: ESA

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