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High Thrust Efficiency MPD Thruster

Award Information

National Aeronautics and Space Administration
Award ID:
Program Year/Program:
2011 / SBIR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
Solicitation Number:
Small Business Information
Tethers Unlimited, Inc.
11711 N. Creek Pkwy S., Suite D113 Bothell, WA 98011-8804
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 2011
Title: High Thrust Efficiency MPD Thruster
Agency: NASA
Contract: NNX11CF67P
Award Amount: $99,987.00


Magnetoplasmadynamic (MPD) thrusters can provide the high-specific impulse, high-power propulsion required to support human and robotic exploration missions to the asteroids, Moon, Mars, and the outer planets. MPD thrusters, however, have traditionally been plagued by poor thrust efficiencies due primarily to power lost into the anode caused by the Hall effect. We propose to combine three innovative techniques to create a high thrust efficiency MPD thruster. The first is an unconventional applied magnetic field geometry that counter the Hall effect near the anode surface, the second is shaping of the electrodes to optimize current uniformity, and the third is "through-anode" propellant injection to prevent depletion of the anode plasma. In prior experiments we demonstrated elimination of the anode fall using these novel magnetic fields, and in recent simulation efforts we developed novel magnetic nozzle designs that succeed in counteracting the current concentrations and plasma starvation effects that cause the anode fall. These magnetic nozzles also showed the ability to increase the amount of axial thrust extracted from the accelerated plasma by over 50%. In the Phase I, we will test the effect of a prototype 'optimized' magnetic nozzle on the thrust efficiency of a MPD thruster; both the magnetic nozzle prototype and thruster test article are already constructed. Additionally, we will develop technology for through-anode propellant injection, and evaluate its performance through tests and simulations.

Principal Investigator:

Robert Hoyt
Principal Investigator

Business Contact:

Robert Hoyt
Business Official
Small Business Information at Submission:

Tethers Unlimited
11711 North Creek Parkway South, Suite D113 Bothell, WA 98011-8808

EIN/Tax ID: 911834561
Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No