NASA SBIR 02-1 Solicitation


PROPOSAL NUMBER:02- S2.05-8886 (For NASA Use Only - Chron: 023113 )
SUBTOPIC TITLE: Optical Technologies
PROPOSAL TITLE: Lightweight High Spatial Frequency Active Mirror Using E Beam Control

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Xinetics Inc.
37 MacArthur Ave
Devens , MA   01432 - 5022
(978 ) 772 - 0352

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Michael Roche
37 MacArthur Ave
Devens , MA   01432 - 5022
(978 ) 772 - 0352

NASA?s Structure and Evolution of the Universe program outlines several missions, such as Terrestrial Planet Finder (TPF) and the Space Interferometry Mission (SIM), that will require the construction and deployment of arrays of telescopes, each potentially 100 to 1000m in diameter, dictating areal densities less than 1kg/m2. Gossamer optics can meet this challenge of affordable, large, lightweight optics. However, due to the difficulties inherent in deploying large scale, thin optics, Gossamer optical systems will require significant technological advances in active wavefront correction. A breakthrough in density, complexity reduction, reliability, and reduced cost per actuator is required for Gossamer systems corrected with adaptive optics. The revolutionary Adaptive Tertiary concept proposed here involves the use of modules, single units of active ceramic with integral electrodes that contain an array of actuator posts with spacings ranging from 1mm to 5mm. The segmented deformable mirror, with up to 349 mirror actuators at 2.5mm spacing in each hexagonal segment, will allow not only the individual correction of errors in any section of the primary optic, but potentially allows a simpler, lighter and less expensive primary to be employed.

In addition to the benefits of hexagonal modules for Gossamer optic system wavefront correction, a segmented deformable mirror would have applications in high energy laser beam cleanup and propagation. The hexagonal array spacing also offers several advantages in conventional adaptive optics applications. The hexagonal packing provides a higher actuator density in a given aperture size and access to influence functions that are not possible with square arrays. Other applications would be in the ophthalmic area. High density mirror arrays could be installed on Fundus cameras to aid ophthalmologists in diagnosing retinal disease and other problems which can be diagnosed through the study of the capillary structure in the eye. There would be applications in laser eye surgery by improving the beam quality of lasers used as scalpels.

The Adaptive Tertiary mirror would allow the correction of wavefront errors in Gossamer optics, which are critical to the development of 100 meter and larger diameter telescopes in space. The adaptive tertiary potentially alleviates some of the tight manufacturing, assembly, and deployment tolerances that are anticipated in working with ultralightweight optics, reducing the complexity of the system and therefore the risk and cost. The adaptive tertiary concept can be applied whether the primary mirror is segmented, as in the case with NGST, or the more typical vision of a continuous gossamer membrane. Each segment of the adaptive tertiary, with independent tip-tilt functionality, can correct both the large errors anticipated during deployment, or the higher spatial frequency errors compensated in a conventional deformable mirror.

Form Printed on 09-05-02 10:10