NASA SBIR 2008 Solicitation


PROPOSAL NUMBER: 08-1 S2.01-8869
SUBTOPIC TITLE: Precision Spacecraft Formations for Telescope Systems
PROPOSAL TITLE: Precise Thrust Actuation by a Micro RF Ion Engine

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Busek Co., Inc.
11 Tech Circle
Natick, MA 01760 - 1023
(508) 655-5565

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Kurt Hohman
11 Tech Circle
Natick, MA 01760 - 1023
(508) 655-5565

Expected Technology Readiness Level (TRL) upon completion of contract: 4

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
Busek proposes to develop a radio-frequency discharge, gridded micro ion engine that produces µN level of thrust precisely adjustable over a wide dynamic thrust range. Rf discharge was chosen to eliminate the life-limiting internal cathode of a dc discharge ion engine. Thrust actuation on the order of 0.03µN resolution is proposed with a closed-loop control system. This controlling scheme can be achieved by varying only one parameter: the rf power with a feedback from the beam current. Uniquely, the rf ion engine can also produce enough thrust for coarse constellation corrections or reconfigurations. Argon will be the base-lined propellant to ease concerns of propellant condensing on optics or other cryogenic surfaces. This feature can be critical for close formation flying as micro-thrusters such as field emission electric propulsion (FEEP) and colloids could potentially coat neighboring spacecraft. The proposed rf ion engine, combined with Busek's space-qualified carbon nanotube field emission cathode (developed for the ST7 DRS mission) as a neutralizer, will create a new opportunity in precise thrust actuation. Further implementation of a simple propellant feed system and power electronics will create a compact, low power, high performance spacecraft propulsion system.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Missions such as LISA, TPF, DARWIN, and the follow on to the GRACE mission, require extremely precise propulsion. Thrust noise will be the largest hurdle in these missions and our proposed thruster can achieve extremely low thrust noise. In addition to precision thrust for optic alignment or similar applications, larger thrust may be required for counteracting solar pressure or reconfiguring the constellation. Precisely varying thrust in a closed loop by the actuation of just one parameter can be a simple implementation with powerful attributes. Because of cryogenic sensors, the propulsion effluent should not thermally radiate or condense on cryogenic surfaces. These considerations lead to the proposed thruster.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Precision propulsion is required by DoD and NRO constellation missions such as the Space Based Radar. Constellations of multiple micro-spacecraft are envisioned to form sparse aperture optics and similar applications. Micro spacecraft have limited power and mass available, thus the thrust actuators must be low power and low mass. The micro rf ion engine can fulfill the requirements. Commercial earth observation missions could achieve greater accuracy and resolution by using the proposed propulsion capable to maintain extremely precise and jitter-free pointing.

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.

Electrostatic Thrusters
Micro Thrusters

Form Generated on 11-24-08 11:56