WASHINGTON -- The Homeland Security Department and top government scientists are testing a new baggage-screening machine capable of identifying liquid explosives, a technology that could put an end to unpopular rules affecting carry-on luggage.
The machine would allow a screener to watch on a computer screen as bags pass through a scanner; suspicious liquids would be flagged with a red dot. The technology is being developed at the Los Alamos National Laboratory in New Mexico and will be tested next summer at Albuquerque's Sunport airport.
If scientists and engineers can make the technology work well in airports, the Homeland Security Department says it may eliminate the requirement that passengers restrict their carry-on liquids to bottles up to 3 ounces that fit in one, quart-size clear plastic bag.
The department acknowledges that the requirement, put in place last September after authorities in London uncovered a plot to blow up U.S.-bound airliners with liquid explosives, is a hassle for passengers and screeners alike.
"We would like to make it a thing of the past," says Brian Tait of the department's science and technology division, which has given Los Alamos $3.3 million to research the technology. "We're going to make the liquids tell on themselves."
The project is called SENSIT (for "sense it") and is based on brain-scanning magnetic resonance imaging, known as MRI.
The scanner, which emits no radiation, uses magnetic signatures to identify the chemicals in liquids at the molecular level.
Liquids determined to be safe show up with a green dot on a computer, those deemed unsafe get a red dot, and those the machine can't identify get a yellow dot. So far, the scanners can identify 50 liquids, some dangerous and some safe.
The Transportation Security Administration (TSA) would have to determine how to handle bags with red and yellow dots, but they would be given further inspection, Tait says.
Los Alamos scientist Bob Kraus says the X-ray machines the TSA uses now can tell screeners whether there is liquid in a bag, but they can't "differentiate between a sports drink and a material ... somebody could use for a bomb."
The new technology can "detect the difference with incredible reliability," he says.
Besides X-ray machines that can find liquids in bags, TSA screeners at 19 airports also are using handheld scanners that can identify some types of liquid explosives, TSA spokeswoman Ellen Howe says.
Next August, the Homeland Security Department plans to run a test at Sunport to see how well the new liquids scanners detect 3-ounce test bottles in a busy airport setting. Passengers' bottles also may be tested.
Kraus says the machines are being built with an end to the 3-ounce limit in mind. "The system we're designing can take everything up to a magnum-size champagne bottle," he says.
