NASA SBIR 2005 Solicitation


SUBTOPIC TITLE:Terrestrial and Extra-Terrestrial Balloons and Aerobots
PROPOSAL TITLE:Hyperspectral Polarimeter for Monitoring Balloon Strain

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Lynntech, Inc.
7607 Eastmark Drive, Suite 102
College Station ,TX 77840 - 4027
(979) 693 - 0017

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Tony   Ragucci
7607 Eastmark Drive, Suite 102
College Station, TX  77840 -4027
(979) 693 - 0017

NASA's latest generation of superpressure, ultra long duration balloons (ULDB) extend the flight time for stratospheric experiments to levels previously unattainable with zero-pressure balloons, while maintaining established load and altitude capabilities. However, the co-extruded polyethylene film structure of these balloon gores must sustain pressure differentials of 240 Pa without loss of structural integrity for 100 days or more. At present, there is no in-situ means for monitoring the strain in balloon gores to determine if a failure is imminent or if corrective action is necessary. Lynntech proposes an optical device which utilizes the birefringence of balloon film, the natural linear polarization of scattered sunlight, and a new technology for producing hyperspectral images to monitor all balloon strain continuously, in-flight, from a single point of reference. The Hyperspectral Polarimeter (HP) will generate real-time strain maps of the balloon by monitoring the birefringence of the gore material, which is linearly proportional to the film strain. An interference spectrum is measured for each pixel of a detection CCD array, enabling the construction of a two-dimensional map of the overall balloon strain. This new, light, and compact technology will enable unprecedented capability for NASA to continuously monitor balloon film strain throughout flights.

The Hyperspectral Polarimeter could be used for in-situ strain analysis on any NASA balloon, including not only the ULDB program but also Long Duration Balloons (LDB) and conventional, zero-pressure balloons, as well. All of these vehicles use thin-film birefringent materials for the balloon gore material, such as polyethylene, polyester, nylon, or some combination of these materials. The device could also be used for testing and evaluation purposes during film fabrication and balloon assembly. Additionally, the core technology of the hyperspectral polarimeter could be extended to design and engineering applications for any NASA device subjected to stress. The traditional technique of photoelastic stress analysis would be substantially enhanced by the precision and absolute quantification capabilities of the hyperspectral polarimeter.

Manufacturers of plastic films could benefit from the highly quantitative quality control analysis capabilities that the hyperspectral polarimeter provides. Applications include retail and commercial plastic bags, architectural sheeting, shatter-resistant glass, adhesive tape, vapor barriers, and air-filled packing material. The device could also be used as a tool for applications where photoelastic stress analysis would typically be used. This includes model machine and structural stress measurement where computational finite element analysis techniques typically fail, such as in threaded engagements and other close-tolerance applications. The precision and absolute quantification of birefringence that the hyperspectral polarimeter provides would enable a level of machine model analysis that is currently unavailable with state-of-the-art photoelastic stress polarimeters.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Autonomous Control and Monitoring

Form Printed on 09-19-05 13:12