NDT.net December 2004, Vol. 9 No.12

NASA NESC Request for Information
Feasible technologies for NDE of foam

NTIAC has been asked to circulate the attached Request For Information (RFI) for NDE of foam. Here's a brief synopsis:

Interested organizations from industry, academia, and government are asked to provide a 500 word abstract describing potentially feasible technologies for NDE of foam. Abstracts will be evaluated and acceptable submittals will be requested to demonstrate current capabilities on samples with known flaws. NASA can provide funding to cover costs incurred in performing the demonstration if needed, and proposals for developmental funding to improve the level of technology readiness will be evaluated by NASA. Chris Coughlin / NTIAC / 415 Crystal Creek Drive / Austin TX 78746 Phone (800)684-2239 or (512)263-2101x227 / FAX (512)263-3530 Email ccoughlin@ntiac.com / Web http://www.ntiac.com

Introduction

The NASA Engineering and Safety Center (NESC) has performed a Technical Review of the Space Shuttle External Tank (ET)thermal protection system (TPS)Manufacturing Program and provided several findings detailing inadequate use of nondestructive evaluation (NDE)in the manufacture of the ET TPS systems.As a result of these findings,the Review Committee recommends expanding efforts to utilize NDE methods that can be demonstrated to detect,locate,and measure flaws in the foam insulation that will assist in the identification of the potential hazard to all critical areas to eliminate critical debris for Return to Flight (RTF),and beyond.The application of quantitative NDE methods which can provide quality assurance to the as applied foam is the highest priority for RTF. The use of in-process monitoring during the manufacturing operations is also of interest since it may allow defects to be found and repaired as they occur,eliminating significant time and effort repairing critical flaws after processing.It is important to pursue potential NDE techniques that can support design or process optimization of the foam and can provide real-time and in situ monitoring and damage characterization for structural durability and life prediction.Lastly, field portable NDE techniques are desired for evaluating post-manufacturing concerns and field installed foam.

Scope of Activity

In order to facilitate the development of NDE methods meeting the needs of the ET TPS Program,it is requested that interested organizations from industry,academia,and government provide a 500 word abstract describing potentially feasible technologies for NDE of foam. Abstracts will be evaluated and acceptable submittals will be requested to demonstrate current capabilities on samples with known flaws. NASA can provide funding to cover costs incurred in performing the demonstration if needed,and proposals for developmental funding to improve the level of technology readiness will be evaluated by NASA.

Desired Capabilities for Potential ET TPS NDE Systems

  • Ability to locate structural defects in Polyurethane foam with a nominal density of 2 pounds per cubic foot,in close proximity to an aluminum substrate and possible adhesive materials
  • One sided inspection from foam side
  • Non-contact methods are acceptable. Contact methods will be considered on a case by case basis.
  • Function around complex geometry and metal protrusions such as stringers and fasteners
  • Fast methods are highly desirable,but can tolerate speeds as low as 1 ft per hour
  • Capable of training inspection technicians to operate and evaluate
  • “Hardenable ” for shop floor or field use

    Defect Detection Requirements

  • Cylindrical voids 0.2 ” diameter x 0.1 ” height under 3 inches of foam on complex substrate (stringers,fasteners,multi-axis curvature)
  • Cylindrical voids 0.5 ” diameter x 0.2 ” height under 8 inches of foam on smooth substrate

    Evaluation Panel Membership

    Potential offerors should understand that government and contractor technical expertise will participate in the evaluations of the proposed NDE techniques.All members of the evaluation team will be bound by appropriate non-disclosure agreements to protect proprietary and source- selection information.

    For further information contact:

    James L.Walker,NASA /MSFC
    EM20
    Marshall Space Flight Center,AL 35812
    256-961-1784 • 256--544-0212 fax
    james.l.walker@nasa.gov

    Please send submissions by COB December 15,2004.
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