NASA SBIR 2002 Solicitation


PROPOSAL NUMBER:02-II 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
115 Jackson Road
Devens , MA   01432 - 5022
(978 ) 772 - 0352

PRINCIPAL INVESTIGATOR/PROJECT MANAGER: (Name, E-mail, Mail Address, City/State/ZIP, Phone)
Michael Roche
115 Jackson Road
Devens , MA   01432 - 4027
(978 ) 772 - 0352

NASA needs larger, lighter optics to achieve the objectives of understanding the Structure and Evolution of the Universe (SEU). Optics of 10-m class and beyond must be active to maintain sufficient optical figure. However, traditional deformable mirrors are too massive and complex to launch into orbit. Electron beam actuation solves this problem by replacing the myriad of wires of current high spatial frequency deformable optics with an electron source. Pointing the electron beam anywhere on the mirror surface provides unparalleled flexibility and unlimited spatial frequency. Phase I results proved the ability to provide high authority, stable and repeatable actuation on an electron beam actuated optic. Flood loading induced 9-waves of power in a 1-in optic. Focusing and pointing the electron beam achieved localized deformations. A scalable design is introduced to allow for a 25-40 cm diameter, less than 5-kg/m2 optic actuated by electron beam control to be delivered on Phase II. The multi-parametric nature of electron beam actuation will be harnessed by developing novel control algorithms. The proposed project will allow for a lower mass, reduced complexity design capable of shape fitting not possible with any current deformable mirror technology, due to the flexibility of electron beam control.

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 10-03-03 11:34