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Technology vs. Terrorism PUBLIC ACCESS

Some of The Best Engineering Brains Offer Antidotes In The Wake Of The Sept. 11 Attacks.

[+] Author Notes

Executive Editor

Mechanical Engineering 124(01), 48-52 (Jan 01, 2002) (5 pages) doi:10.1115/1.2002-JAN-3

This article focuses on how NASA is studying the ways of aircraft safety in times of troubles. Besides investigating aircraft safety, NASA searches for life beyond Earth. The agency is evaluating ways in which its biological and chemical sensors might give the average security person a very rapid analysis. Such devices need to provide “human-centered output” and tell security workers “what to do next” following identification of a chemical or biological agent. NASA plans to work with the Federal Aviation Administration to evaluate ideas like installing multilevel security in airports or combining chemical and biological sensors into dosimeter-like devices that are cheap, tiny, and fast. NASA’s chief technologist, Samuel Venneri, who took on the agency’s added role of associate administrator in 2000, said NASA was investigating algorithms for creating “protective bubbles” around prohibited areas so aircraft avoid obstacles on approach to landing. Such algorithms would guide flights along “precision curved paths,” possibly helping to alleviate current airport capacity problems as well.

Remember total recall? Arnold Schwarzenegger’s skeleton packs an automatic through a detection tunnel on his way to Mars. Then there’s the chestnut about the kid who has to land the plane while the ground controller talks him down.

Those ideas aren’t as far out as they used to be. In fact, you may not even need the kid at the stick.

Venneri: Protective bubbles around prohibited areas can avert disaster.

Grahic Jump LocationVenneri: Protective bubbles around prohibited areas can avert disaster.

Airliners programmed to land themselves in time of trouble or airport security passages with batteries of chemical sensors and CAT scans were only some of the ideas tossed out by a hightech panel at the New York Sheraton during the ASME International Mechanical Engineering Congress and Exposition.

O'Bryon: Airplanes can refuse to crash.

Grahic Jump LocationO'Bryon: Airplanes can refuse to crash.

It was exactly two months to the day after terrorists attacked the World Trade Center and the Pentagon that the panel of experts assembled by Mechanical Engineering editors spoke to hundreds of engineers in a special session, “Technology vs. Terrorism: Designing Against the Threat of Assault.”

NASA’s chief technologist, Samuel Venneri, who took on the agency’s added role of associate administrator in 2000, said NASA was investigating algorithms for creating “protective bubbles” around prohibited areas so aircraft avoid obstacles on approach to landing. Such algorithms would guide flights along “precision curved paths,” possibly helping to alleviate current airport capacity problems as well.

NASA has a Boeing 757 aircraft that it uses for research, Venneri said. With this plane the agency studied wind shear some years ago. The agency plans to use the plane next to demonstrate protections against hostile pilots bent on turning commercial aircraft into “precision guided missiles.”

The agency is studying ways of knowing where aircraft are at all times, Venneri said. It was looking at methods to make systems harder to tamper with and was exploring new ways of alerting pilots to trouble, he said.

Besides investigating aircraft safety, NASA searches for life beyond Earth. The agency is evaluating ways in which its biological and chemical sensors might “give the average security person a very rapid analysis,’’ he said. Such devices need to provide “human-centered output” and tell security workers “what to do next” following identification of a chemical or biological agent.

NASA plans to work with the Federal Aviation Administration to evaluate ideas like installing multilevel security in airports or combining chemical and biological sensors into dosimeter-like devices that are cheap, tiny, and fast.

James O’Bryon discussed a system available now that prevents military jets from making “controlled flights into terrain.” The phenomenon is common enough to warrant its own acronym, CFIT.

O’Bryon, who is deputy director of operational test and evaluation for the Department of Defense’s live fire test program, said the majority of military aircraft crashes occur outside of combat. Pilots in tight maneuvers sometime succumb to g-loc, or g-induced loss of consciousness. Under such conditions, CFIT can be moments away.

By making military aircraft more forgiving of the frailties of warm-bloodedness, an automatic ground avoidance system relieves a blacked-out pilot until he can drift back up to consciousness.

The system is already used on the Swedish Gripen, O’Bryon said. The United States has tested it, too, on a high-speed F-16 fighter diving straight toward the Mojave, its afterburners lit. Fourteen times the pilot tried to crash it and 14 times the aircraft flew itself clear of disaster, he said.

The system displays to the pilot two chevrons that move sideways toward each other as ground avoidance prepares to take charge. The system then counts down the seconds, starting at five. After removing the plane from danger, it tells the pilot: “Back to you.”

What could such a system do for a commercial aircraft? In defending against kamikaze terrorism, the system buys time, O’Bryon said. If someone can’t crash the plane, that allows ground control to take over, he said. Such a system could not only eliminate controlled flight into terrain, it could deter suicidal hijackers.

John Andersen, a member of the ASME Board of Governors, is chairman of AFlightTech Inc., a company that is refining and marketing an advanced aircraft guidance system developed by a group of engineer/pilots. AFlightTech has other lines of business, including investigation of air crashes.

The guidance system, called Required Navigation Performance, is “an FAA-approved system for accurate guidance of aircraft along a precisely defined path,” Andersen said. The system was originally conceived as a way of making flight safer and more efficient.

Required Navigation Performance, or RNP, replaces traditional instrument flying with a variety of systems, including ground proximity warning, traffic collision avoidance, inertial guidance, and global positioning. The information from these and other advanced technologies keep the aircraft flying tightly on a programmed course.

Andersen: Programmed flight resists error.

Grahic Jump LocationAndersen: Programmed flight resists error.

RNP programs have been licensed by the Federal Aviation Administration to be used on 12 runways in Alaska, where the technology helps pilots negotiate difficult terrain in harsh landing conditions. The company is working on programs for other airports, including San Francisco International Airport and Ronald Reagan Washington National Airport in the District of Columbia, and plans to seek FAA approval for those routes in the near future.

The system will keep an aircraft tightly on a programmed flight path, with much closer tolerances than are possible with traditional line-of-sight methods and flight instruments, Andersen said. RNP is accurate enough to permit parallel landings even in poor visibility, he said. That would let an airport operate at normal capacity in bad weather.

It will also permit aircraft to use routes that are now impractical because of obstacles. The navigation and referencing equipment keep a plane true to its course with a fraction of the deviation involved in conventional air navigation, he said. As a result, planes equipped with the system can spend less time and fuel in skirting potential hazards, or each other.

The RNP system was developed without terrorists, suicidal or otherwise, in mind. But according to Andersen, it is readily adaptable to a security role. For instance, the system keeps positive track of the airplane, and with little change could be able to alert ground controllers of any deviation from the flight plan. An alarm could be made automatically and without alerting anyone aboard the aircraft, he added.

Hallowell: Sensors will raise airport security.

Grahic Jump LocationHallowell: Sensors will raise airport security.

With a little more engineering, the system can be equipped with an emergency autopilot secured by coded controls. In this case, the crew facing an invasion of the cockpit or other onboard hazard can turn over management of the airplane to the RNP computer, which cannot be overridden without a code that is known only to key personnel. “With coded crew-only access to the RNP flight equipment, a distressed aircraft could not be redirected to a target of terrorist opportunity,” Andersen explained.

Such a technology would require “a change in culture,” he admitted. At present, FAA rules and the inclination of pilots prohibit handing over control of a plane irrevocably to a CPU.

The system can be enhanced with an automated emergency landing sequence, so a plane can be brought in according to its program, automatically and without human intervention, in emergencies when the pilots can’t take control.

Susan F. Hallowell, who manages R&D projects into explosives and weapons detection for the FAA, envisions an airport of the future in which the narrow metal-detecting gates disappear, to be replaced by tunnels full of sensors. Passengers walking through the passages are screened not only for weapons, but also for signs of explosives, bio-agents, and a raft of other contraband that can do harm.

Currently, FAA researchers are working on chemical detectors that security-gate personnel can use just like the hand-held wands they now wave to check for metal on individual travelers. The explosives used in bomb-making leave behind a residue that is readily apparent on a person’s clothes or skin, or anything that has come in contact with the chemicals.

The wands would check for chemical residue, Hallowell said. In the future, fliers might walk through a hightech chimney that emits a puff of air to lift chemicals from clothes. Technology included in the chimney would then screen for traces of the ingredients from explosives or chemical weapons.

There is detection technology, including CAT scanners and electron-beam tomography, that could be used today, or in a short time at least, if money was dedicated to put it in place. It’s possible to design multispectral sensors that can detect small concealed objects on people, Hallowell said.

She cautioned, though, that what is possible isn’t necessarily acceptable. “I don’t know if this technology will be acceptable to the traveling public,” she said. Some may balk at exposure to radiation; others may object to the invasion of privacy. There are other considerations, too. “The trick is to render high-level security, but to keep the costs down and to make it fast,“ she said.

For that reason, Hallowell praised what she called the advent of miniaturization, which may usher in a new age in airport security detection. “MEMS and nanotechnology will revolutionize much in our lives, including security,” she said. “I don’t expect to see nanotechnology sensors in airports during my professional lifetime ... but certainly it’s the next generation.”

Security devices also must be user-friendly, she said. The data have to be clear to screeners and interpreters, who must be able to read the information accurately and quickly enough to respond.

Christopher W. Aston is a molecular biologist involved in neuroscience research and is an adjunct professor at the New York University School of Medicine. He says he came to the study of biological weapons, or “black biology,” through his biomedical research, which uses many of the same detection technologies.

Aston: Microspheres uncover bio-agents.

Grahic Jump LocationAston: Microspheres uncover bio-agents.

According to Aston, a large-scale biological attack is unlikely. (Recent events would tend to underscore the point. The attempts to spread anthrax through the U.S. mail, as harrowing as they may have been, resulted in 18 confirmed infections, including five deaths, over the course of two months.)

Biological weapons are regarded as a threat primarily on battlefields, where soldiers need warning in time to put on protective gear, Aston said. A current method is to mount a laser telescope on a helicopter to watch for the release of aerosols.

There are various tests possible for detecting and identifying biological agents. A biochemical test, for instance, is specific and sensitive, but can detect only previously characterized agents.

Tissue-based tests can detect unknown agents in seconds, but require cultured cells grown in labs. The cells are fragile, and the technology is not currently in use in the field.

Chemical mass spectrometry, which scans the molecular composition of a substance, is another possible method not currently deployed. The data it returns are difficult to analyze, Aston said.

Yet another test method, still in the experimental stage, uses treated microspheres, called addressable beads, to test for numerous agents at once. The microspheres carry molecular tags that attract them to specific biological agents. By observing the behavior of the beads, technicians not only can detect the presence of a biological agent, but also identify it.

Aston said the United States “leads the world” in developing detection technologies, but added that the country seems content to rely on devices without random checks or other means of overseeing labs that are the source of chemical agents.

Jim Zarzycki, as technical director of the U.S. Army Soldier and Biological Chemical Command, oversees about 1,500 researchers whose mission includes defense against chemical and biological weapons. About a third of them, he said, are engineers—primarily, mechanical and chemical—and their work is preparing for a threat of bio-terrorism.

A key to avoiding or counteracting bio-weapons is to detect a presence and, if possible, to identify it before it can have time to work.

A current sampling method is to take a sponge treated with a phosphate-buffered saline solution and wipe down a surface, for example, an envelope. An identification method, much like the common pregnancy test, will cause a positive sample to turn a predetermined color, perhaps purple for anthrax. The materials can be supplied in a simple field test kit.

A more sensitive technique, polymerase chain reaction, uses chemicals to open the biological particles in a sample, isolate their DNA, and amplify it for detection.

The armed services are particularly interested in defending against a biological weapon that may be delivered by missile warhead over a military position without the troops’ knowledge.

Zarzycki (left) seeks long-range warning of bio-agents; Goswami would turn them into CO2 and H20.

Grahic Jump LocationZarzycki (left) seeks long-range warning of bio-agents; Goswami would turn them into CO2 and H20.

A field device to detect a biological attack can sample the air at a rate of 1,000 liters per minute continuously. It screens particularly for particles in the range of 1 to 10 micrometers, small enough to enter the lungs. These particles undergo the scrutiny of an ultraviolet laser, which can identify biological content. A spike in biological activity could trigger further, more specific testing.

This type of device is an example of point detection, Zarzycki said. It is deployed upwind of the position it protects and collects samples from the air around itself.

Standoff detection, such as a laser system that can scan dust clouds at a distance, can provide earlier warning. An infrared laser can detect changes in clouds as far as 10 km away. Artificial intelligence in the system can compare the image of the cloud with a database containing patterns of various biological weapons.

A second wave of detection comes from an ultraviolet laser, which has a range of about 3 km. At that point, the UV laser trained on a suspicious cloud can determine whether it is made of biological or nonbiological material. It cannot distinguish pollen from anthrax, but it can provide a warning that something potentially hazardous is on the way.

D. Yogi Goswami, professor of mechanical engineering at the University of Florida and an ASME Fellow, said that discovering anthrax in Sen. Tom Daschle’s office recently was scary enough, but finding it in other Senate offices was even scarier. He posed the question: What do you do about deadly aerosols? “That’s precisely where engineering comes in,” he said. “Mechanical engineering to be more precise.”

Goswami was referring to applying a photocatalytic technology that he originally developed for his asthmatic son. He said that it can be adapted to destroy airborne bio-agents.

The history of the device began with Goswami’s efforts to ease his son’s discomfort. After a fruitless study of available air filtration technologies, the professor of engineering decided to use sunlight, which can decontaminate water, to destroy airborne allergens.

The drawback to air filters, explained Goswami, is that, although they can trap aerosols such as volatile organic compounds, spores, and bacteria larger than 0.8 micron at greater than 99 percent efficiency, trapped biological contaminants are very much alive and multiply in the filter.

Light at a certain wavelength can excite a catalyst to create hydroxyl radicals, said Goswami, who compared them to “bullets for micro-organisms.” These powerful oxidizing agents break the toughest chemical bonds, and convert biological agents into carbon dioxide and water.

Goswami’s team built a prototype decontamination system consisting of a recirculating duct, titanium dioxide (an ingredient of toothpaste) as the catalyst, and black light, a staple of psychedelic visual effects in the 1960s. During the first stages of experiment, the team introduced micro-organisms into the system, which was able to destroy them all in 10 to 12 hours.

Goswami used standard mechanical engineering fluid enhancement procedures, including monitoring and improving flow pattern and turbulence to maximize contact between the catalyst and the aerosols, to do the job in three minutes.

According to Goswami, an additional benefit of photocatalytic ventilation treatment is that the process eliminates dead bacteria by converting them to C02 and water. This is important because some dead bacteria emit toxins.

Later, the University of Florida researchers introduced mold, a very tough bacterium to kill, into their photocatalytic treatment system. The mold spores were evaporated upon contact with the catalyst, Goswami reported.

As is typical practice, the design team did not test deadly anthrax in the decontamination system, but a close relative with similar characteristics. According to tests conducted by an independent laboratory, there was 100 percent bio-aerosol removal, with nothing growing on the filter, Goswami said. Similar results were obtained in eliminating the volatile organic compound acetone from the system.

Goswami said that a commercial version of his photocatalytic treatment can be installed in the prefilter of a ventilation system to eliminate airborne contaminants.

Hightower:Water is a national concern.

Grahic Jump LocationHightower:Water is a national concern.

The final speaker of the evening, Michael Hightower, a civil and environmental engineer at Sandia National Laboratory in Albuquerque, N.M., joked that “you got a guy from the desert here to talk about water.”

On a more serious note, Hightower noted that Sandia, a national security laboratory, is working with the Environmental Protection Agency and the Department of Defense to adapt the protective methodologies that Sandia originally developed for nuclear weapons to shield water supplies from terrorist attack.

Over the next 15 years, “over half of the world’s population will be living in areas that are water-stressed,” he said. “Some people are even talking about water becoming the oil of the 21st century.” For these reasons, water was already emerging as a national security concern, which only increased after Sept. 11.

Hightower outlined two major vulnerabilities of U.S. water systems: many are very old, and they are open. New York, for instance, relies on tunnels over 100 years old to bring drinking water to the city from reservoirs 120 miles away. “That’s tough, to guarantee the safety and security of something that distributed,” he said.

Hightower cautioned that many threats against the nation’s water supply were not credible and should be put into perspective. “You can’t have a person with a backpack come up and really contaminate a reservoir,” he said. A chemical spill of 50,000 or 100,000 gallons, on the other hand, could disrupt water service for days.

By taking the risk assessment and probability assessment methodologies originally devised for nuclear weapons and applying them to threats to water treatment plants, Sandia has identified emerging research needs to protect water supplies. These needs include sensor-based monitoring systems, electromechanical control systems to deliver water and stop its flow in an emergency, improved treatment technologies—such as mass membranes at plants or filters on taps—improved water system design and security from computer intrusion and other sources of tampering.

There is a need to integrate biological and chemical water treatment, because most water treatment systems do one or the other, but not both, Hightower said.

A recurring theme among speakers was the potential involvement of listeners.

The moderator of the discussion, Tom Goldstein, dean of Columbia University’s Graduate School of Journalism, pointed out that, because newspapers and television do not routinely cover engineering as a beat, the contributions of engineers are often unseen, and so are unknown, by the population at large. He admitted that it was specifically because of his preparation for the event that he was “brought up to speed in a hurry” on the pervasive influence of engineering. But he added that the situation may have changed, at least for a while. “In the last couple of months, I do believe the public has become much more aware of the vital role engineers play,” he said.

The attacks in September took their greatest toll of life in New York City, where it is now believed about 3,000 died. Engineers from various disciplines made significant contributions in New York’s response to the disaster, a city official said.

John Odermatt of the New York Office of Emergency Management addressed the assembly as a representative of the city. He reported that large numbers of engineers had volunteered immediately after the towers were struck in New York.

Hundreds of investigations needed to be done, and done quickly, to determine the structural stability of buildings surrounding the World Trade Center. The big question was how much damage neighboring structures suffered from the heat or perhaps from debris of the collapsing towers.

Many buildings outside the World Trade Center complex, which was completely destroyed, were quickly found to be sound. According to Odermatt, it was because of the work of those engineers that “we were able to give back a lot of those buildings and start our recovery process.”

The headquarters of Odermatt’s own agency, one of the keystones to the city’s response, were in the World Trade Center and were destroyed with the towers.

O’Bryon, clearly aware that he was talking to engineers, ended his remarks by reminding the audience that the government is looking for ideas that may help the war on terrorism.

Hallowell took it a step farther. She said that her lab outside Atlantic City isn’t only looking for ideas from the public, but also for people. “I’m actually down a few engineers,” she said.

Copyright © 2002 by ASME
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