NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 X6.06-9634
SUBTOPIC TITLE: In-Space Propulsion (Electric/Magnetic)
PROPOSAL TITLE: Optimized Magnetic Nozzles for MPD Thrusters

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Tethers Unlimited
11807 North Creek Parkway South, Suite B-102
Bothell, WA 98011-9803

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Robert Hoyt
11807 North Creek Parkway South, Suite B-102
Bothell, WA 98011-9803

Magnetoplasmadynamic (MPD) thrusters can provide the high-specific impulse, high-power propulsion required to enable ambitious human and robotic exploration missions to the Moon, Mars, and outer planets. Whereas the thrust and power densities of Hall and Ion thrusters are limited by space charge effects, MPD thrusters can process very high power levels while providing high specific impulse thrust. MPD thrusters, however, have traditionally been plagued by poor thrust efficiencies. These inefficiencies are due primarily to power lost into the anode caused by the Hall effect. TUI proposes to apply innovative techniques for using applied magnetic nozzles to eliminate these anode power losses and dramatically improve the performance of MPD thrusters. In the proposed Phase I effort, TUI will develop magnetic nozzle designs optimized to maximize the thrust efficiency of MPD thruster systems, minimizing anode fall power losses and maximizing the efficiency of plasma detachment from the magnetic nozzle. In the Phase II effort, we will build and test prototypes of these magnetic nozzles, and obtain definitive measurements of their enhancement of MPD thruster efficiencies.

The magnetic nozzle technology will improve the efficiency of MPD thrusters, enabling them to generate the high-Isp, high-thrust, high-efficiency propulsion required to enable NASA's exploration programs to perform ambitious, large-delta-V missions using nuclear electric or solar electric propulsion. MPD thrusters with the magnetic nozzle technology will provide large cost savings relative to current chemical propulsion technologies. Because they can process far greater power densities than Hall or Ion thrusters, MPD thrusters can achieve the high thrust densities and high thrust-to-mass propulsion necessary for Manned Mars missions, fast Mars cargo delivery, and missions to the outer system such as the Europa probe and the Pluto mission.

The magnetic nozzle technology developed in this SBIR effort will enable MPD thrusters to achieve the thrust efficiencies necessary for commercial applications such as solar-electric propulsion for orbit raising of commercial satellites. Terrestrial spin-off applications will include materials processing applications such as ablation or etching, surface annealing and hardening, and efficient power switching technologies. The proposed PI has already demonstrated success in commercializing a materials processing application of magnetically nozzled MPD thruster technology.