Helium-filled airships eyed as spying tool

April 02, 2005|By JON VAN.

The federal government, which has done spy-in-the-sky satellite surveillance for years, is looking for something a little more down to earth.

People in the military and in homeland security would like surveillance platforms overhead at a distance higher than airplanes but not as far as space. They want helium-filled airships that could hover in one spot for a year at a time, watching the world below.

By perching closer to the ground, the surveillance equipment could get a better look at the goings-on below. Also, the airship would serve as a skyborne antenna and switching station for radio communications used by military, police and emergency personnel.

These communications/surveillance airships could be put in place over large urban areas like Chicago and above the nation's borders.

A team of engineers and scientists at Purdue University is working to make this happen within the next five years. Academic researchers will design and build models of the craft, and government agencies could contract with an aerospace firm to build the actual airships.

Building a giant, unmanned airship that will fly some 65,000 feet above Earth will require integrating a lot of existing technologies in ways that really push the envelope, said John Sullivan, an aeronautics professor who is co-leader of the project.

"Putting something up there and keeping it stationary is a challenge," he said. "You cannot do it with something shaped like the Goodyear blimp."

The airship, which could be as much as 900 feet long, will need to have photovoltaic cells on its skin to convert sunlight to electricity. It also will need to carry fuel cells that can generate power when sunlight is unavailable.

Computer scientists are developing models to determine the size and shape of the craft, as well as determining how much power the various systems will require to operate.

Existing motors and electronics needed to fly the airship and to support its surveillance and communications functions are too heavy and use too much power to be feasible, Sullivan said. "We're pushing for new, lighter-weight materials with greater energy efficiencies," he said.

To test some early ideas, the Purdue team has built one model that can fly at a few thousand feet. Graduate students and undergraduates are working on the project with faculty from a variety of Purdue departments.

"It's a lot of fun," Sullivan said. "Students really like it. We usually work on airplane design. Flying an airship at 65,000 feet is difficult, and it pushes the boundaries, but there are fewer complexities to an airship than an airplane.

"It's a fascinating project."

Cancer clue found: A relatively simple test to not only diagnose cancer but also forecast its aggressiveness is being developed by scientists at the University of Illinois at Chicago.

Researchers studying malignant cells found abnormalities on the outside of the cells that prevent enzymes from reaching the DNA inside.

Scientists regularly use the enzymes to manipulate genetic material. The more malignant the cell, the more resistant it was to the enzyme.

"In invasive cancers, segments of DNA are so twisted and compacted that the enzyme can't get access," said Andrew Maniotis, assistant professor of pathology.

This finding should lead the researchers to develop a test to diagnose cancer and could lead to new strategies for treating it.