Iowa State University scientists explore the frontiers of NASA science

AMES, Iowa -- The science is tiny as carbon nanotubes and the silica shells that cover single-cell algae. And it's as practical as finding a leak in a spacecraft and understanding a new material for the next space telescope.

Researchers affiliated with Iowa State University's Center for Nondestructive Evaluation are working on 17 projects for the National Aeronautics and Space Administration. The work is in its fourth year and is focused on finding new materials to monitor the health and safety of spacecraft and developing new methods for inspecting spacecraft. The research projects are supported by $7 million appropriated by Congress from 2002 to 2005.

"This research is laying the foundation for the future," said R. Bruce Thompson, an Iowa State Anson Marston Distinguished Professor in Engineering and director of the Center for Nondestructive Evaluation. "Space is a whole new area to apply our toolbox and develop new tools."

Here are four examples of the research Iowa State scientists are doing for NASA:

  • Leak detection
  • It's not easy to find a leak in a spacecraft. The leaks can be caused by collisions with tiny meteorites or orbiting space debris. The noise of pressurized air escaping a spacecraft shoots into the vacuum of space. Besides, spacecraft walls are covered with gear, instruments, gadgets and tools. So it once took astronauts two weeks to find a leak in the International Space Station.

    Dale Chimenti, an Iowa State professor of aerospace engineering, and Ronald Roberts, a scientist at the Center for Nondestructive Evaluation, are working on measurement and computing technology that can detect and pinpoint leaks in about 30 seconds. Chimenti said the system detects the minute vibrations produced by the skin of a spacecraft when pressurized air escapes in a turbulent rush. Taking measurements from two locations allows researchers to use triangulation to pinpoint the leak.

  • Carbon nanotubes
  • The tubes are strong, light and potentially useful for electronic and mechanical applications. But they're tiny, just a few atoms across. They're very smooth, too. So it's a challenge for researchers to work with them, let alone put them to good use.

    Vladimir Tsukruk, a professor of materials science and engineering, is working to wrap the tubes with a long-chain polymer. That should help researchers handle and align carbon nanotubes. And that could allow carbon nanotubes to be used as sensors on spacecraft. Such sensors could be used to examine the gases in a spacecraft's air. Tsukruk said carbon nanotube sensors would be much smaller and much lighter than existing technologies.

  • New space materials
  • NASA is designing a new composite material that will be used to construct some of the structures on the next generation of space telescope, the James Webb Space Telescope. The new composite is a polymer reinforced with two types of carbon fiber.

    David Hsu, a senior scientist at the Center for Nondestructive Evaluation, is using ultrasonic technology to test the composite so researchers have a better grasp of its properties. He's also testing the composite after it was exposed to temperatures down to minus 424 degrees Fahrenheit. Hsu is using ultrasound technology to study micro cracking caused by the thermal tests.

  • High-tech nature
  • Nanotechnology is pushing technology smaller and smaller. And that makes it harder and harder to produce 3-D materials for nanotechnology applications. How do you make holes, crevices and rims on structures only a few millionths of a meter across?

    Mufit Akinc, professor and chairman of materials science and engineering, is working with the tiny silica shells created by microscopic, single-celled algae called diatoms. He's using chemical vapors to turn the silica shells -- which come in thousands of shapes -- into compounds such as titania and barium titanate. Akinc said the compounds and their fancy shapes have potential for use in micro devices and sensors.

    Other Iowa State projects for NASA include development of new magnetic sensors for spacecraft, study of new materials for advanced sensors, improvements in X-ray techniques for early detection of cracking in spacecraft and development of computer simulation tools to assist NASA with ultrasonic inspections.

    Akinc said the NASA projects provide some interesting work for Iowa State scientists.

    Yes, he said, "It's also fun to work on these things."