NASA SBIR 2006 Solicitation


SUBTOPIC TITLE:Guidance, Navigation and Control Beyond Low Earth Orbit (LEO)
PROPOSAL TITLE:Reaction Wheel Disturbance Model Extraction Software

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Nightsky Systems, Inc.
3916 Lauriston Rd
Raleigh, NC 27616-8612
(919) 261-0936

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Sonia   Ensenat
3916 Lauriston Rd
Raleigh, NC  27616-8612
(919) 217-4829

TECHNICAL ABSTRACT ( Limit 2000 characters, approximately 200 words)
Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized. Disturbances can be amplified by wheel and other structural dynamics (for example, isolator modes), that are coupled to gyroscopic effects and therefore are wheel speed dependent. Tonal disturbances and wheel structural modes thus sweep across a frequency band. When one or more tones crosses the frequency of an observatory mode, a large jitter response will result. These higher harmonic effects have not been very significant in the past, for larger spacecraft having looser pointing requirements. However, many current and planned missions have much tighter pointing requirements than past missions. The higher harmonic wheel disturbances are being found to interact with structural modes to cause jitter exceedances. The lack of knowledge of higher harmonic wheel disturbance behavior forces engineers to carry more conservatism in the observatory design, resulting in potentially higher costs. The proposed innovation is a modeling tool that will create a hybrid physical/empirical wheel disturbance model from reaction wheel Induced Vibration data, suitable for high-confidence on-orbit jitter prediction.

POTENTIAL NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
NASA is planning many future observatory missions that would benefit from a reliable RW disturbance modeling capability. A short list includes the Terrestrial Planet Finder Interometer (TPF-I), Single Aperature Far Infrared Observatory (SAFIR), Vision Mission ? Stellar Interferometer (VM-SI), Thirty Meter Space Telescope (TMST), Fourier-Kelvin Stellar Interferometer (FKSI), and the Space Infrared Interferometric Telescope (SPIRIT). All of these missions pose the challenge of a large, lightweight aperature with extremely tight pointing requirements.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
The Earth observing community would benefit from the RWDMES technology.

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.

Structural Modeling and Tools

Form Printed on 09-08-06 18:19