NASA SBIR 2011 Solicitation


PROPOSAL NUMBER: 11-2 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: 4
End: 5

TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
In the Phase I program, Busek Co. Inc. tested an existing Hall thruster, the BHT-8000, on iodine propellant. The thruster was fed by a high flow iodine feed system, and supported by an existing Busek hollow cathode flowing xenon gas. The Phase I propellant feed system was evolved from a previously demonstrated laboratory feed system. Throttling of the thruster between 2 and 11 kW at 200-600V was demonstrated. Testing has shown that the efficiency of iodine fueled BHT-8000 is the same as with xenon, with iodine delivering slightly higher thrust to power (T/P).

Plume current was also measured at a variety of operating conditions. Preliminary design work for a new thruster to be built in Phase II was also completed.

In Phase II a complete iodine fueled system will be developed including the thruster, hollow cathode, and iodine propellant feed system. The nominal power of the Phase II system is 8 kW. However, it can be deeply throttled as well as clustered to much higher power levels. The technology can also be scaled to >100 kW per thruster to support MW-class missions. The target thruster efficiency for the full scale system is 65% at high Isp (~3000 s) and 60% at high thrust (Isp~2000 s). These projections are based on Phase I testing and prior testing of higher power thrusters.

Iodine enables dramatic mass and cost savings for lunar and Mars cargo missions, including Earth escape and near-Earth space maneuvers. High purity iodine is available commercially in large quantities at much lower cost than xenon. Iodine stores at 2 to 3 times greater density than xenon and at approximately one thousandth of the pressure and may be stored in low mass, low cost propellant tanks instead. Passive, long term storage of a fully fueled system is feasible including storage in conformal tanks which may be used to shield internal components against some types of space radiation.

POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
The proposed thruster 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 to NEOs, Asteroids, comets, and planets. The demonstrated throttling ability of iodine is important for a singular thruster that might be called upon to propel a spacecraft from Earth to Mars or Venus. The ability to throttle efficiently is even more important for missions beyond Mars.

Another possible NASA application is re-boosting the ISS, a mission which is currently accomplished by inefficient chemical propulsion.

For high power exploration missions (hundreds of kW or greater), the system would be increased in size and/or clustered. Destinations of interest include the Moon, Mars, asteroids, and NEOs.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Integrated with a high power commercial spacecraft, the proposed thruster could accomplish all required propulsion functions including orbit raising, orbit circularization, inclination changes, station-keeping and repositioning. All aspects of a GTO to GEO transfer are possible.

The thruster would be also very well sized for a high power electric upper stage for a commercial launch vehicle. The high stored density of iodine leads to much lower system volume than with xenon or other conventional alternatives.

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.)
Active Systems
Coatings/Surface Treatments
Isolation/Protection/Radiation Shielding (see also Mechanical Systems)
Isolation/Protection/Shielding (Acoustic, Ballistic, Dust, Radiation, Thermal)
Lifetime Testing
Maneuvering/Stationkeeping/Attitude Control Devices
Models & Simulations (see also Testing & Evaluation)
Pressure & Vacuum Systems
Simulation & Modeling
Spacecraft Design, Construction, Testing, & Performance (see also Engineering; Testing & Evaluation)
Spacecraft Main Engine

Form Generated on 09-03-12 17:04