Airport Security Technology Stuck In the Pipeline

They also complained about the difficulty in getting scientists, bureaucrats and top officials to sign off on devices.

Mark Laustra, vice president of homeland security for Smiths Detection, said it "can be a bit of a maze to get from concept through development."

"The TSA has to review all potential technologies and test them to see if they are practical for the checkpoint," Laustra said, adding that he thinks the government sufficiently funds development of emerging technology. "This process takes time, and then the lab and others like homeland security and TSA have to agree to pilot a program."

Various factors have complicated the deployment of other high-tech gadgets. After the 2001 attacks, so-called backscatter X-ray devices were hailed by security experts as a critical tool in finding explosives. The machines work by scanning a passenger with a low-intensity X-ray beam that provides screeners with a photograph of what lies underneath the traveler's clothing.

Although the machines have been in commercial service for at least a decade, their deployment has been delayed several times because officials were worried about violating passengers' privacy.

The TSA has taken steps to shield passengers' privacy by erecting closet-sized, windowless rooms where screeners study backscatter images but cannot see the passenger. That installation process alone costs more than $20,000, TSA officials said.

The TSA also has mandated that vendors blur the images of the passengers, a move that the manufacturers and security experts have said might result in a screener missing an illicit item.

The devices, which cost more than $100,000 a piece, have other limitations. For example, they take about 45 seconds to complete a scan, a time lag that would probably lead to massive checkpoint congestion if they were installed in main security lines.

Hawley said he sees promise in backscatter devices but expressed more enthusiasm for another emerging technology: millimeter wave machines, which can see through clothes by analyzing the reflection of radio frequency energy bounced off passengers.

One such device is being tested in Phoenix, and the TSA has announced plans to buy eight more for $1.7 million to test at other airports. It works much faster than backscatter, which may open the door to using it as a primary screening device like the magnetometer, Hawley said. But it also requires the TSA to construct separate rooms and to train screeners to analyze its images, which are not as clear as those produced by backscatter.

"There is no perfect technology," said Hawley, who is also taking a less ambitious approach to upgrading checkpoint X-ray machines.

Rather than buy expensive machines that are similar to those scanning checked luggage, Hawley has opted to buy 250 less-sophisticated X-ray machines that take at least two views of a carry-on bag instead of the single view generated by current machines. Hawley said that will give screeners a better shot at finding banned items.

Most will be deployed by the end of the year, Hawley said, adding that their software can be easily upgraded to adapt to emerging threats.