Every Last Drop
By: Nicole Lundberg
New water-recovery technology could be used in manned space missions.
Sending a single can of soda into space costs thousands of dollars. This means, when planning space missions, every ounce counts.
The average person uses at least 233,600 pounds of water in one year, according to the U.S. Geological Survey. At that rate, bringing enough water to sustain even a short manned mission to Mars would be astronomically expensive.
Texas Tech researchers have developed a solution: a reactor that recycles wastewater and recovers every last drop.
”Most filtration systems recover about 60 to 80 percent of the wastewater,“ said Andrew Jackson, a professor and associate chair in the Department of Civil, Environmental, and Construction Engineering. ”Our reactor recovers 100 percent of the water.“
Audra Morse, a professor in the Department of Civil, Environmental, and Construction Engineering, said her team partnered with Paragon Space Development Company to create the Integrated Water Recovery Assembly (IRA). This reactor, which is funded by a Small Business Technology Transfer Research (STTR) award from NASA, is the first biological wastewater treatment system designed for space missions.
”Biological systems are a new area for NASA,“ Morse said. ”We have worked on these biological systems in a variety of mission scenarios for more than a decade. Now we are providing NASA with data that proves the reliability of these systems.“
Biological treatments have several advantages over other filtration systems that could be used in space, Morse said. Most water purification techniques use chemical-physical systems, much like water filters used in refrigerators. While these filters effectively purify water, they also create waste.
”If your refrigerator filter needs to be replaced, you go to the hardware store and put in a new filter canister,“ she said. ”When NASA uses systems like this, they have to store all of the material that cannot be reused and enough new material to last the entire mission. That is a lot of mass to transport.“
Because the microbes in Texas Tech's bioreactor reproduce, NASA would not have to replace them during a mission, Morse said. They also live at the same temperatures and pressures as the astronauts, so there are no added energy costs.
The IRA works much like wastewater treatment plants on Earth. In many treatment plants, bacteria break down organic materials in sewage, which is then treated and returned to the water supply, he said.
While the Earth's water treatment systems served as a baseline for the researchers, developing a similar system for space presented new challenges, Jackson said. For example, space is a microgravity environment. Because Earth's water treatment systems use gravity to move water from one part of the purification process to another, researchers had to develop different methods of moving water.
The researchers also had to consider space constraints and consumables.
”On Earth, you can build a massive system, and if that system creates waste, it is OK because you have a place to put that waste,“ he said. ”In space, you have limited room, you cannot create waste, and there is no gravity. ”
Working with Paragon, the researchers developed the IRA, which meets all of these requirements, he said. The bacteria that purify the wastewater grow on tubes that send oxygen throughout a container. The system is self-contained, which means it will be portable.
While the IRA is designed for space applications, it could also provide clean water during natural disasters, Jackson said. The military could also use the system to supply water to remote bases, where transporting water can cause security issues.
The system is not yet ready for deployment, but laboratory demonstrations have been successful, Jackson said. He and Morse both said that they believe the technology could change the future of space travel.
”This project is exciting because we are having an impact,“ Morse said. ”Our technology has potential to influence NASA's future missions.“