Water test in space

University of Utah chemists have developed a two-minute water-quality monitoring system that has recently started six months of tests aboard the International Space Station.

At present, water on the space shuttle is brought back to Earth for analysis. But monitoring it in real time with an onboard monitor will eliminate the delays involved.

According to Marc Porter, a chemistry professor at Utah, 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 colour of the membrane with a commercially available, handheld colour sensor normally used to measure the colour and glossiness of automobile paint.

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

Porter said: ‘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.’

As a spin-off, the test is being modified so it can quickly check water for the level of arsenic – a natural pollutant in places such as Bangladesh and the southwest and northeast of the US –and it can be adapted to quickly and inexpensively test for other pollutants such as chromium, cadmium, nickel and other heavy metals.

Each handheld device – two were in the kit taken to the space station in August – weighs 1.1lb, runs on four AA batteries, has a readout screen and measures 7 x 3.7 x 3.2in.

The project was funded by NASA, 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