by Brenda Polk, MTU News Bureau Student Writer
HOUGHTON, MI--Researchers are refining improvements in the water processing system for the International Space Station that could save NASA millions in the years ahead.
The team of David Hand, John Crittenden, and David Hokanson- -all of Michigan Tech University--is currently modeling the process to optimize the system.
The water processing system needs to treat 110 pounds of water per day. The waste water is cleaned by a process of multiple filtrations through resins and adsorbents so that the final product is ready for potable use.
"Our strategy is to optimize this multifiltration unit design and come up with a way to make it more efficient," says Hand, "and currently, the columns only last about 30 days." When water exiting the filters fails to meet certain standards, a new column is sent up to space by NASA.
To send anything up into space, NASA spends $15,000-20,000 per pound, according to Hand. By designing a column that will last longer, potential savings reach about $1,000,000 per year, he says.
"We're working on the present design to save money on expendables," says Hand. Using models as a guide, the team is trying to design an efficient column that is smaller, has a longer use period, and will be cheaper all around.
What they have found is that the water is mostly clean after going through about 2/3 of the filters. The problem is to find the most efficient combination of ion exchange resin(s) and adsorbent(s) that will provide the longest filter life.
"Our modeling studies," says Hand, "have helped us understand the process mechanisms so that we can design the most efficient process." The models can also be used to simulate the treatment columns' performance when unexpected changes in the waste streams occur.
Funding for the research is provided by the NASA Ames Research Center and Ion Electronics, Inc.