Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New System Tests Water Quality in Orbit

Space is not a fun place to get a stomach bug. To ensure drinking water is adequately disinfected, University of Utah chemists developed a two-minute water quality monitoring method that just started six months of tests aboard the International Space Station.

“Now they bring water back on the space shuttle and analyze it on the ground. The problem is there is a big delay. You’d like to be able to maintain iodine or silver [disinfectant] levels in real time with an onboard monitor,” says Marc Porter, a University of Utah professor of chemistry and chemical engineering.

The new method involves sampling space station or space shuttle galley water with syringes, forcing the water through a chemical-imbued disk-shaped membrane, and then reading the color of the membrane with a commercially available, handheld color sensor normally used to measure the color and glossiness of automobile paint.

The sensor detects if the drinking water contains enough iodine (used on U.S. spacecraft) or silver (used by the Russians) to kill any microbes. The International Space Station has both kinds of water purification systems.

“Our focus was to develop a small, simple, low-cost testing system that uses a handheld device, doesn’t consume materials or generate waste, takes minimal astronaut time, is safe and works in microgravity,” says Porter.

As a spinoff, the test is being modified so it can quickly check water for the level of arsenic – a natural pollutant in places like Bangladesh and the U.S. Southwest and Northeast – and it can be adapted to quickly, inexpensively test for other pollutants.

“It is a general method,” says Lorraine Siperko, a senior research scientist in Porter’s laboratory. “It could be used on the ground for testing all kinds of water contaminants such as arsenic, chromium, cadmium, nickel and other heavy metals.”

The method is easy to use and much cheaper than existing tests, says Porter.

From the ‘Vomit Comet’ to the Shuttle to the International Space Station

The water-monitoring system fits in a pack the size of a small ice chest. It was launched Aug. 28 on space shuttle Discovery bound for the International Space Station.

The project is funded by the National Aeronautics and Space Administration, the Utah Science, Technology and Research (USTAR) economic development initiative and two universities where Porter worked previously: Arizona State and Iowa State. The project team now includes NASA, USTAR and the University of Utah, Iowa State University and Wyle Laboratories. Porter is a professor hired under the USTAR program.

During the past decade, the water quality monitoring method was developed and tested during about two dozen low-gravity flights on NASA’s “vomit comet” research aircraft such as the KC-135 and C-9, which took off from Ellington Air Force Base in Texas. During a flight, each plane makes 40 parabola-shaped arcs through the sky, climbing steeply, then leveling and diving. Weightless conditions exist for about 30 seconds at the top of each arc.

Porter rode the KC-135 twice in 2002 and 2004, and became very motion sick. Siperko rode the C-9 five times in 2006 and 2007, developing and testing the water-quality monitoring technique, including how to remove drinking water samples from collection bags without excessive bubbles, which don’t easily separate from water in weightless conditions. The handheld sensor and chemicals used in the testing process also were checked for reliability during the low-gravity plane flights.

Now, “the experiment is in space for the first time,” Siperko says. “It’s very rewarding and exciting to know that something you worked on is so important that NASA put it on the shuttle for a six-month test on the International Space Station.”

Porter called the space station “the coolest place to do experiments.”

On the space station, “once per month they will check the water for iodine and silver,” Siperko says. “That data will be downloaded and relayed back to Earth, to Johnson Space Center” in Texas.

“We have teleconferences with them, and they will transfer the data to us electronically for us to look at,” she adds. “That way we can judge if the experiment is working correctly. If any unforeseen problems arise, then we can advise them as to what we think might be the problem and how to correct it.”

Keeping It Clean in Orbit

The project began a decade ago, before Porter joined the Utah faculty, when NASA sought proposals for disinfectant or “biocide” monitors to check the safety of drinking water on manned spacecraft.

“You can’t sterilize water well enough to keep things from growing in it,” Porter says. “Nature happens.”

NASA uses iodine as a disinfectant on U.S. spacecraft. The Russians use colloidal silver – pure silver nanoparticles, some of which go into solution.

The problem for both iodine and silver is that microbes grow in the water if levels are too low. If levels are too high, iodine-treated water tastes bad and eventually might cause thyroid problems, and silver at excessive levels can turn the skin grayish blue.

Space station water now is sampled and returned to Earth for testing at intervals of months because “they don’t have an acceptable onboard technique,” Porter says.

He says the space station is a proving ground for technologies for longer manned flights to the moon and Mars – even though those flights are unlikely anytime soon due to high costs and other priorities.

Water for astronauts is carried into orbit and also produced on the space station as a byproduct of hydrogen and oxygen reacting in fuel cells. Disinfectants or biocides are added during flight, but actual levels in drinking water cannot be tested until samples are brought back to Earth. Porter says required biocide levels in drinking water are 0.1 to 1 part per million silver and 0.1 to 5 parts per million iodine.

How It Works

To test whether drinking water is adequately disinfected, space station astronauts will collect galley water in sealed plastic bags, and then use syringes to remove some water from the bags and push it through a cartridge that contains a half-inch-diameter, polymer, porous-membrane disk impregnated with a chemical to detect either iodine or silver. The disks, known as “solid phase extraction membranes,” capture either iodine or silver, depending on the chemical in the disk.

Next, the bottom half of the cartridge, which contains the disk, is placed against a German company’s handheld “diffuse reflectance spectrometer,” which shines light on the disk so it can read the disk’s color in about two seconds. Porter says the device was developed to measure the reflectivity or gloss, and thus the quality, of finishes such as automotive paint, industrial surfaces, stainless steel and decorative metals.

Each handheld device – two are in the kit taken to the space station – weighs 1.1 pounds, runs on four AA batteries, has a readout screen and measures 7 inches by 3.7 inches by 3.2 inches.

To test for iodine, the disk is impregnated with PVP (polyvinylpyrrolidone), a nontoxic chemical in contact lens cleaning solutions. The PVP reacts with iodine, and the intensity of the resulting yellow color reveals the concentration of iodine in the water.

To test for silver in water, the disk is imbued with DMABR, which is short for 5-(dimethylaminobenzylidene)rhodanine. A yellowish color indicates silver is absent, while flesh to brighter pink reveals how much silver is present.

“We can do this whole analysis in about two minutes on the ground or in space,” Porter says.

-- Marc Porter, USTAR professor of chemistry and chemical engineering – office (801) 587-1505, cellular (801) 831-4282,
-- Lorraine Siperko, senior research scientist – office (801) 587-1522, cellular (801) 865-1189,

-- Lee Siegel, science news specialist, University of Utah Public Relations – office (801) 581-8993, cellular (801) 244-5399,

Lee Siegel | Newswise Science News
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>