NASA SBIR 2011 Solicitation

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)
Lawrence Byrne
larry@busek.com
11 Tech Circle
Natick, MA 01760 - 1023
(508) 655-5565

Estimated Technology Readiness Level (TRL) at beginning and end of contract:
Begin: 3
End: 4

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
In response to Topic S3.04 "Propulsion Systems," Busek proposes to develop a high throughput Hall effect thruster with a nominal peak power of 1-kW and wide throttling range in terms of both power and Isp. In Phase I, we will design the thruster, focusing on achieving a magnetic field that shields the discharge channel from ion induced erosion. Our goal is to achieve a propellant throughput of at least 100 kg per kW of input power and a system specific mass of 6 kg per kW. Numerical modeling will play an important role in the thruster design to achieve these lifetime targets. Erosion predictions will be validated by comparing model results to measurements taken in a nominal 600 W thruster during an accelerated lifetime test scheduled take place in 2011 at NASA GRC under separate funding.

In Phase II, we build and test a laboratory model thruster capturing the essential magnetic field criteria. The performance, lifetime, and plume properties of the thruster will then be evaluated, and the design will be optimized. Our goal is to reach TRL 5 by the end of Phase II.

The complete flight system built in Phase III will include a high power thruster, a hollow cathode, and a propellant feed system. However, the focus of this program will be the thruster.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The proposed system has many applications both as a stand-alone system and as part of a much larger (higher power) cluster.

On its own, the thruster will be well suited for orbit raising and interplanetary transfers, supporting exploration and science missions. The demonstrated throttling ability is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. Mars orbits at 1.52 AU, which reduces the solar constant to 43% of the value at Earth. Venus orbits at 0.72 AU, which increases the solar constant to 190% of the value at Earth. As a result the output power of a nominal 600 W array varies between 260 W and 1.15 kW as a spacecraft travels between these planets. The ability to throttle efficiently is even more important for missions beyond Mars.

The thruster may also be used for orbit raising and circularization (including GTO to GEO transfers) and inclination changes. In GEO, the thruster may be used for station-keeping and repositioning.

On its own, the thruster is well sized for primary propulsion on ESPA-sized spacecraft (~180 kg). Clustered, the thruster will support larger, higher power spacecraft and systems, such as a small electric upper stage.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Commercial applications for the proposed system include orbit raising, circularization, inclination changes, repositioning, and station-keeping. For higher power missions, the system would be clustered. Commercial applications for a clustered system include a small electric upper-stage. Other applications include a system for de-orbiting spacecraft that have reached their end of life.

TECHNOLOGY TAXONOMY MAPPING (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.)

Lifetime Testing Maneuvering/Stationkeeping/Attitude Control Devices Models & Simulations (see also Testing & Evaluation) Prototyping Relative Navigation (Interception, Docking, Formation Flying; see also Control & Monitoring; Planetary Navigation, Tracking, & Telemetry) Simulation & Modeling Spacecraft Design, Construction, Testing, & Performance (see also Engineering; Testing & Evaluation)