20mN, Variable Specific Impulse Colloid Thruster
Project Description
During Phase I, Busek designed and manufactured an electrospray emitter capable of generating 20 mN in a 7" x 7" x 1.7" package. The thruster consists of nine porous-surface emitters operating in parallel from a common propellant supply. Each emitter is capable of supporting over 70,000 electrospray emission sites, with the plume from each emitter being accelerated through a single aperture, eliminating the need for individual emission site alignment to an extraction grid. The total number of emission sites during operation is expected to approach 700,000. Phase II results will focus on optimization and characterization of the thruster fabricated during the Phase I effort, as well as fabrication of additional porous emitters for full-scale testing. Propellant will be supplied to the thruster via existing feedsystem and micro-valve technology previously developed by Busek, under the NASA ST7-DRS mission, and follow-on electric propulsion programs. Methods for extending thruster life beyond the previously demonstrated 450 hours, will be investigated and include potential alternate emitter materials selection, and bi-polar thruster operation. The life extending capabilities will be demonstrated on a sub-scale version of the thruster developed.
More »Anticipated Benefits
Primary NASA applications include missions requiring exceptional thrust/power in power-limited missions, and missions benefiting from variable specific impulse (200-2000+seconds) and variable thrust (10x throttling). In many cases, the proposed colloid thruster may prove superior to most other electric propulsion technologies in nearly all metrics for power levels <200 Watts (where thruster efficiency has greater impact on total system efficiency).
The primary non-NASA application for the proposed thruster is to support development of colloid-based multi-mode propulsion using green monopropellants, where there is a lack of suitable thrusters at the milliNewton level or greater. This allows a spacecraft to utilize shared propellant tanks for high thrust chemical propulsion as well as high Isp electric propulsion, and is particularly attractive for small spacecraft with limited mass and volume for multiple propellant tanks. Additional applications include replacement of some of the lower thrust plasma-based electric propulsion devices, which suffer from decreased efficiency at low power due to unfavorable surface-to-volume scaling. The variable Isp capabilities and higher thrust levels provide a useful multimode solution for spacecraft requiring both dwell/stationkeeping as well as rapid maneuvers from a single propulsion system.
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Busek Company, Inc. | Lead Organization |
Industry
Women-Owned Small Business (WOSB)
|
Natick, Massachusetts |
Glenn Research Center
(GRC)
|
Supporting Organization | NASA Center | Cleveland, Ohio |
Primary U.S. Work Locations
-
Massachusetts
-
Ohio
