Featured Research

from universities, journals, and other organizations

Rensselaer Researchers Use T-rays To Uncover Defects In Space Shuttle Foam Sample

Date:
June 12, 2003
Source:
Rensselaer Polytechnic Institute
Summary:
Using a technique pioneered by researchers at Rensselaer Polytechnic Institute, terahertz (THz) radiation has been used to uncover small defects in a sample of space shuttle foam. This nondestructive method could help National Aeronautical and Space Administration (NASA) officials examine the insulating foam that is applied to each shuttle's fuel tank prior to launch.

TROY, N.Y. -- Using a technique pioneered by researchers at Rensselaer Polytechnic Institute, terahertz (THz) radiation has been used to uncover small defects in a sample of space shuttle foam. This nondestructive method could help National Aeronautical and Space Administration (NASA) officials examine the insulating foam that is applied to each shuttle's fuel tank prior to launch.

Fuel tank manufacturer Lockheed Martin Space Systems (New Orleans) approached X.-C. Zhang, the J. Erik Jonsson Professor of Science at Rensselaer, and requested a study of a sample of the foam material. Zhang and his research team have employed terahertz radiation (T-rays) to spot defects, including air bubbles and separations, purposely embedded in a specially prepared sample. Such defects have proved difficult to locate using X-rays or ultrasound. Zhang's team (including doctoral students, Hua Zhong, Xie Xu, Tao Yuan, and Shaohong Wang) has been working closely with Lockheed Martin to study the sample. The sample is composed of material identical to that which would be applied to the shuttle fuel tank. In contrast to the continuous layer of foam normally applied to the tank, the sample is a block measuring two feet square and approximately four inches thick. An aluminum plate serves as the base for two different insulating materials: A one-inch layer of dense, cork-like Super-Lightweight Ablator (SLA) is applied on top of a three-inch layer of closed-cell Sprayed-On Foam Insulation (SOFI).

A total of eight man-made defects of various sizes were scattered throughout the sample. The embedded imperfections mimic defects that could potentially occur in a normally produced foam application on the fuel tank. Two types of defects were hidden in the sample: voids (or air bubbles), ranging from one-quarter inch to one inch in size, and debonds (separations between layers of foam or between a foam layer and the aluminum base).

NASA investigators believe that the Columbia space shuttle crash may have been caused by foam insulation breaking away and striking the left wing of the craft.

A New Way to See

The technology behind the emitters and detectors used to produce and sense the T-rays was developed at Rensselaer. The researchers use electro-optic crystals and a femtosecond laser to generate and detect the THz signal. They are able to locate and identify defects in the insulating foam sample by measuring the signal amplitude, temporal delay, and waveform distortion of the signal.

Optimal THz scan sensitivity also depends on the material being looked at. Thickness and density of an object can affect how far the T-rays will penetrate and how widely they will scatter. Both the SLA and SOFI materials making up the insulating foam sample happen to be excellent subjects for THz radiation, says Zhang. "The foam has a lower attenuation, allowing the terahertz waves to penetrate to a depth of many inches."

T-rays lie within the far-infrared region of the electromagnetic spectrum – the large range between microwaves and visible light. The unique properties of THz radiation make it a potentially excellent complement to existing imaging methods such as X-rays and ultrasound. The safety and sensitivity of T-rays may allow the technology to someday play a part in security searches for weapons and toxins, and could improve detection of breast and skin cancer.


Story Source:

The above story is based on materials provided by Rensselaer Polytechnic Institute. Note: Materials may be edited for content and length.


Cite This Page:

Rensselaer Polytechnic Institute. "Rensselaer Researchers Use T-rays To Uncover Defects In Space Shuttle Foam Sample." ScienceDaily. ScienceDaily, 12 June 2003. <www.sciencedaily.com/releases/2003/06/030612090906.htm>.
Rensselaer Polytechnic Institute. (2003, June 12). Rensselaer Researchers Use T-rays To Uncover Defects In Space Shuttle Foam Sample. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2003/06/030612090906.htm
Rensselaer Polytechnic Institute. "Rensselaer Researchers Use T-rays To Uncover Defects In Space Shuttle Foam Sample." ScienceDaily. www.sciencedaily.com/releases/2003/06/030612090906.htm (accessed September 2, 2014).

Share This




More Matter & Energy News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins