Cosmic currents: Preserving water quality for astronauts during space exploration

November 13, 2023

On Nov. 9, the SpaceX Falcon rocket streaked skyward from Kennedy Space Center in Florida, bound for the International Space Station (ISS). The rocket is on a commercial resupply mission dubbed CRS-2 SpX-29. In addition to providing vital provisions for astronauts, SpX-29 carries a special biological sciences payload — a collaborative experiment developed by researchers at Arizona State University, Texas State University (TSU) and NASA to study how spaceflight affects bacterial growth and biofilm formation in life support systems on the ISS.

This experiment will provide scientists with information to help improve spacecraft habitat sustainability — specifically, protection of one of the most vital and vulnerable resources aboard any space vehicle: water. The International Space Station. The International Space Station is an orbiting oasis of science and multicountry unity. On Nov. 9, the SpaceX Falcon rocket streaked skyward from Kennedy Space Center in Florida, bound for the International Space Station to investigate Escherichia coli and Pseudomonas aeruginosa — two microbial pathogens that could potentially pose a risk to astronauts and spaceflight systems due to the aggregation of these bacteria into sticky residues known as biofilms. Graphic by Jason Drees Download Full Image

The results from this study will provide critical insights for future spacecraft design, life support systems operations and crew health. Controlling biofilms, sticky communities of microbes that adhere to surfaces, is critical to protect the integrity of life support systems that provide water that is safe for drinking and personal hygiene.

The research also promises to shed light on the subtleties of bacterial behavior under reduced gravity conditions, as well as bacterial activities here on Earth, many of which remain poorly understood.

The two model pathogenic microorganisms featured in the study, Escherichia coli and Pseudomonas aeruginosa, have been detected in the past aboard the ISS, and both are associated with causing biofilms in water lines. Limiting or eliminating such bacterial pathogens from the water supply is essential for the health and safety of the crew as well as the integrity of mission-critical systems during spaceflight.

In a series of groundbreaking experiments, Cheryl Nickerson (co-principal investigator, ASU), Robert McLean (principal investigator, TSU) and their colleagues explore the risk of biofilm formation on stainless steel surfaces like those in the ISS water system, the potential for system corrosion, and the effectiveness of microbial disinfection in order to validate the results of their earlier spaceflight research.

“We are honored that NASA selected our team’s research for a rare reflight opportunity to the International Space Station,” Nickerson says. “This provides us the chance to validate the results from our previous flight study to understand and control the impact of the spaceflight environment on interactions between microbes and their habitat. It also reflects the importance of this work to NASA’s goals to protect human health and habitat sustainability in spaceflight.”

Cheryl Nickerson

Biodesign researcher Jiseon Yang, a contributor to the new mission, says, "Understanding the resilience of multispecies biofilms is important to ensure the health of astronauts and the durability of life support systems during extended space travel. This research aims not only to support the success of future deep space exploration but also provides profound implications for water treatment and corrosion control on Earth."

Nickerson is a professor with the School of Life Sciences and a researcher in the Biodesign Center for Fundamental and Applied Microbiomics at Arizona State University. 

Nickerson and McClean are joined by co-investigators Jennifer Barrila (assistant research professor, ASU) and C. Mark Ott (lead microbiologist, NASA Johnson Space Center), as well as Jiseon Yang (assistant research Professor, ASU), Richard Davis (ASU), Sandhya Gangaraju (ASU), Taylor Ranson (Texas State University), Starla Thornhill (NASA JSC) and Alistair McLean.

The project is a unique collaboration between ASU, TSU and NASA, and represents one of the few cases of joint funding between NASA’s Space Biology and Physical Sciences divisions.

Space germs and their threat

The new study, dubbed BAC (for bacterial adhesion and corrosion), will investigate two spaceflight hazards associated with microbially contaminated drinking water. The first is a health threat to the spaceflight crew, caused by E. coli and P. aeruginosa, both potent biofilm formers, which can cause disease at high enough concentrations. Since bacteria in biofilms are known to be resistant to disinfectants and antibiotics, it makes them difficult to remove and treat. This is important given that the rigors of spaceflight depress the immune system and some pathogens increase their disease-causing potential in spaceflight. This means that space travelers are potentially more susceptible to infectious disease.

The second concern is a safety threat, since microbial biofilms in water can be corrosive, degrading essential components and compromising spaceflight systems over time.

The project is a rare opportunity for researchers to double-check results of their previous BAC spaceflight study from 2020 and further fine-tune recommendations for ensuring continuous availability of safe water in space.  

As NASA and other organizations contemplate longer and more complicated endeavors in space, including return voyages to the moon and potential trips to Mars, the issue of water integrity during spaceflight is more pressing than ever. Any water-related mishap during extended spaceflight is a potentially lethal emergency.

Water: Vessel of illness and health

Here on Earth, contaminated water is the source of many life-threatening infectious diseases, including cholera, typhoid fever, enteric salmonellosis and dysentery. A complex infrastructure has been constructed to ensure the water we are exposed to is safe.

During spaceflight, however — far from the comfort of our home planet — the importance of safeguarding this precious resource becomes even more critical, and the challenges far more daunting.

Water resources in space are tracked carefully, including the recycling, purification and reuse of urine, wastewater and even sweat. Despite the extravagant lengths taken to ensure water aboard the ISS is safe, bacterial microbes are tenacious foes and will try to find a footing in water supplies or on material surfaces, where they can multiply. Different types of bacteria can join forces to create aggressive biofilms that are resistant to efforts to eradicate them with antimicrobials.

Lab in the sky

The experiments will track the growth of E. coli and P. aeruginosa within specially designed containers over a 117-day period aboard the ISS. The study will evaluate the formation of biofilms when the two pathogens are combined, which is relevant to how biofilms naturally develop in mixed populations. The tests will evaluate bacterial biofilm development during an early, middle and late phase over the course of the spaceflight.

Additionally, some of the biofilms will be exposed to silver disinfectant, to see how well this addition acts to limit growth and biofilm formation. The results will help guide NASA’s future decisions for microbial control of water resources using silver in the water systems as opposed to iodine, which is the current anti-microbial of choice.

The researchers will also examine biofilm formation on stainless-steel materials like those used in the ISS water system to see whether biofilm formation is acting to corrode them. A final evaluation explores bacterial gene expression during spaceflight, shedding light on how microgravity and other spaceflight conditions may be guiding bacterial behavior at the molecular level.

Challenges for safe water

Aboard the ISS, the Environmental Control and Life Support System uses an advanced process to purify water. This intricate procedure starts with a primary filtration step to sift out particles and detritus. Following this treatment, the water flows through layers of multi-filtration beds, which are designed to absorb and eliminate both organic and inorganic contaminants. The final stage eradicates volatile organic substances and exterminates any microorganisms present.

Even with such advanced life-support mechanisms in place to safeguard the water supply, bacterial populations have proven adept at circumventing these barriers, with some establishing resilient biofilms within the ISS water purification system.

Biofilms present significant global socioeconomic challenges, leading to extensive health and industrial issues, with financial repercussions soaring into billions of dollars annually here on Earth. They are responsible for clogging oil and chemical processing lines, contaminating invasive medical devices like stents, triggering infections and polluting water supplies. Furthermore, biofilms can aggressively corrode numerous materials, including stainless steel, which is a component of the ISS water system, thereby jeopardizing its integrity.

Although the ISS water harbors many of the same microorganisms that are present in terrestrial drinking water, conditions in space raise worries that these microorganisms could become more dangerous. One specific concern is related to the effects of microgravity — a factor that researchers from the same team have found to potentially increase the harmfulness and stress tolerance of certain pathogens.

Alterations of bacterial genes under spaceflight conditions could lead to a better understanding of how biofilms develop with translational potential to control biofilms on Earth and in space. Such investigations further underscore the value of space-based platforms for gaining new insights in life and health sciences.

Richard Harth

Science writer, Biodesign Institute at ASU


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ASU's Indian Legal Program grows into nationally recognized institution

November 13, 2023

Program that trains scholars in Indian law celebrates 35 years

When William C. Canby Jr. looks back at Arizona State University’s Indian Legal Program's humble beginnings, he openly marvels at how far it has come.

“When I first came to ASU, the law school had six professors on staff and our faculty meetings were held at a small table at a hotel coffee shop on Apache Boulevard,” said Canby, a senior judge for the United States Court of Appeals for the Ninth Circuit and a founding faculty member of the Sandra Day O’Connor College of Law and the Indian Legal Program.

“It’s become quite an institution since then," he said. "This program has grown in so many ways. They have more resources, there’s more outreach and they are attracting great students to practice Indian law to populations around the country. I’ve been so lucky to see it come to fruition.”

Canby was the centerpiece of the Indian Legal Program’s 35th anniversary, which kicked off with his Nov. 9 presentation “Indian Law Today and Tomorrow, From a Long-Term Perspective.” His lecture was part of a three-day celebration that included a legal education session, dinner and silent auction, and a golf tournament to raise money for a variety of student scholarships and endowments.

“The ILP is proud to honor Judge Canby through this annual law school lecture,” said Kate Rosier, executive director of the Indian Legal Program. “Judge Canby, a founding faculty member of the law school, was the first person to teach Indian law at ASU. Through his teaching and his early partnerships with tribal governments, he laid the foundation for the strong program we have become.”

The annual lecture was started in 2007 to honor the 92-year-old Canby, who served two years as an U.S. Air Force judge, clerked for Associate Justice Charles Evans Whittaker on the U.S. Supreme Court, spent a few years in the Peace Corps in Africa, was a special assistant to Sen. Walter Mondale, and was an assistant to Harris Wofford, president of State University of New York at Old Westbury. In 1980, President Jimmy Carter appointed Canby to the Ninth Circuit Court.

“Judge Canby is a giant in Indian law as he was the second person in the United States to teach Indian Law at a university,” said Robert J. Miller, faculty director of the Rosette LLP American Indian Economic Development Program and a professor at ASU Law. “He has visited tribes around the state and got them to work with ASU. His book, 'American Indian Law in a Nutshell,' has been read by every law school student and judge in the field, which is going into its eighth edition. He is also the founding member of the leading Indian law program in the country, and is still going strong.”

Canby said he stumbled upon his legal niche fortuitously, and quite by accident.

“I was hired by Dean Willard H. Pedrick, who had been at ASU for a year and trying to get things set up. I was told to get here by July 1, so he could go on vacation but have someone watching the shop while he was away. He was going to make me acting associate dean for a month,” Canby said. “I wasn’t here but a week when someone from the regional office of the Bureau of Indian Affairs came to Tempe. He wanted to bring tribal judges from Arizona, Utah and Nevada here and have someone give them a day’s instruction to give them some general instruction on law. I said, ‘I’ll do it.’”

Canby and the judges met eight to nine times a year for several years. In 1971, Warren Cohen joined the faculty, and together, the duo created the informal Office of Indian Law. Under this name, they began to increase outreach and foster relationships with tribes, often funding their activities from their own pockets. The relationship grew and tribes began to seek out advice and guidance from the program.

“Judge Canby saw a need with tribes with their codes and their courts and he agreed to meet with them on these issues and worked with their communities,” said Patty Ferguson-Bohnee, Indian Legal Program faculty director and a clinical professor of law. “He saw a need for public service to tribal governance and he met it. Ever since then, the ILP has hired dedicated faculty to educate Native students and others who are interested in Indian law.”

In 1988, the Indian Legal Program was accredited by ASU President J. Russell Nelson, giving birth to the official name. The program moved to ASU’s Downtown Phoenix campus and has been housed in the $130 million Beus Center for Law and Society since 2016.

“This is the seventh academic year we’ve been able to work in this beautiful law school building,” said Stacy Leeds, Willard H. Pedrick Dean and Regents Professor of Law at the O’Connor College of Law. “But it’s not just the law school and the physical space that distinguishes us from our peers. We are so fortunate to have grown but also sustain what is undoubtedly the nation’s best Indian law program.”

Today the program's faculty includes 10 professors (six of whom are full-time Native American law professors), three faculty associates and seven staff members. Through their expertise, they offer a variety of degrees and law certificates, as well as hosting national conferences, workshops, lectures, presentations and community outreach programs. 

The Indian Legal Program is also the home of the Indian Legal Clinic, Tribal Court Trial Skills College, Pathway to Law Initiative, Continuing Legal Education courses, the Rosette, LLP American Indian Economic Development Program and the ILP Washington, D.C. Experience, which offers students an opportunity to take classes for a full semester in the nation’s capital.

To date, the program has graduated approximately 400 students, representing 151 tribes. Some of the more notable graduates include Benjamin Hanley, who served 13 two-year terms to the Arizona State House of Representatives; Claudeen Bates Arthur, the first Navajo woman licensed as a lawyer in the United States and first female chief justice of the Navajo Supreme Court; Diane Humetewa, a U.S. District Court judge and the first Native American woman and enrolled tribe member to serve as a federal judge.

In 2010, Derrick Beetso joined that list of distinguished graduates.

“As an alum, I always thought that some point in my career I might come back to ASU and transition back into academia,” said Beetso, director of the the program's Indian gaming and self-governance programs, and a professor of practice at ASU Law. “We have an opportunity to provide to a broad spectrum of students from very talented faculty. When I think of Judge Canby and the Indian Legal Program, it reminds me of that old saying: We stand on the shoulders of giants.”

Top photo: The second day of the anniversary celebrations for the Indian Legal Program included a Nov. 10 dinner and silent auction. All proceeds went to support Indian Legal Program students with scholarships. Photo by Tabbs Mosier/ASU