Skip to main content

Use of focused pulse-echo ultrasonics for non-destructive inspection of thick carbon-carbon structures

Buy Article:

$25.00 plus tax (Refund Policy)


The reinforced carbon-carbon (RCC) heat shield components on the Space Shuttle's wings must withstand harsh atmospheric re-entry environments where the wing leading edge can reach temperatures of 3000F (about 1650C). Potential damage includes impact damage, micro cracks, oxidation in the silicon carbide-to-carbon-carbon layers, and interlaminar disbonds. The thick, carbon-carbon and silicon-carbide layers in the heat shield panels are difficult to inspect and existing techniques were deemed to be inadequate. Since accumulated damage in these structures can lead to catastrophic failure of the Shuttle's heat protection system, it became imperative for NASA to develop quickly an acceptable health monitoring programme. NASA selected a multi-method approach for inspecting the wing leading edge which includes eddy current, thermography, and ultrasonics. Sandia Labs produced the in-situ ultrasonic pitch-catch inspection method. Optimum combinations of custom ultrasonic probes and data analysis were merged into the overall inspection method needed to properly survey the heat shield panels. Comprehensive validation tests revealed that the ultrasonic pitch-catch inspection system is capable of reliably finding flaws of 0.25 diameter or less in the heat shields. The inspection system is now in use at NASA to complete Return-to-Flight certification inspections prior to each Shuttle launch.

Document Type: Research Article


Affiliations: Sandia National Labs, New Mexico, USA.

Publication date: December 1, 2006

More about this publication?

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more