NASA SBIR 2011 Solicitation


PROPOSAL NUMBER: 11-1 X2.03-8838
SUBTOPIC TITLE: Electric Propulsion Systems
PROPOSAL TITLE: Iodine Hall Thruster for Space Exploration

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)
James Szabo
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)
Busek Co. Inc. proposes to develop a high power (high thrust) electric propulsion system featuring an iodine fueled Hall Effect Thruster (HET). The system to be developed will include a thruster, hollow cathode, and condensable propellant feed system. The nominal power level of the thruster developed in this program will be 20 to 50 kW. The thruster can be clustered to support ~200 kW class missions to the moon, Mars, and beyond. In a future program, the technology can be scaled to ~100 kW per thruster to support MW-class missions. The available specific impulse can be throttled between 1500s to will be as high as 3000 to 4000 s. The use of iodine propellant enables significant mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. High purity iodine is readily available commercially in large quantities at a fraction of the cost of xenon. Iodine stores at a density that is 3 times greater than xenon and at less than one thousandth of the pressure. Thus, iodine may be stored in low volume, low mass, low cost propellant tanks instead of the relatively large, high pressure, high cost COPV tanks required for xenon Hall thruster systems. Busek has already demonstrated a low power (several hundred watts) iodine thruster system based upon its flight qualified BHT-200 thruster. At most points, the efficiency are the same or nearly the same given experimental uncertainty. However, iodine may have a significant performance advantage at high power: Iodine yielded significantly higher specific impulse and thrust to power at higher input power. This effect will be investigated with the proposed high power system.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The proposed 20 to 50 kW thruster system has many applications both as a stand-alone system and as part of a much larger (higher power) cluster. 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 10 kW array varies between 4.3 and 19.1 kW as a spacecraft travels between these planets. The ability to throttle efficiently is even more important for missions beyond Mars.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
For DoD missions, including orbit raising for high power satellites and upper stages, the customer is the Air Force, via other defense contractors. A decade ago, the Air Force Research Laboratory (AFRL) initiated a program to cluster HETs as a means to reach the 100 kW to 150 kW power range desired for orbit transfer vehicles, space tugs, and re-supply vessels.

Busek is working on the design an upper stage based upon the ESPA ring. A high power iodine Hall thruster system will would enable a high throughput (propellant mass >1200 kg), high delta-V orbit transfer stage based upon the ESPA ring. To carry more than ~450 kg of propellant, the system would have to be fitted with additional Xe propellant tanks that hang on the outside of the ring. With iodine, the ring could easily contain over 1200 kg of propellant.

For truly commercial activities, such as GTO to GEO transfers, the customers are commercial satellite vendors and operators. Other potential customers are the emerging satellite servicing ventures such as MacDonald Dettwiler SIS and Vivisat.

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.)
Maneuvering/Stationkeeping/Attitude Control Devices

Form Generated on 11-22-11 13:43