Claims
- 1. A pulsed plasma thruster propellant module comprising:
at least one propellant rod including:
a first stage having a first propellant source having dimensions defining a first stage discharge length; a second stage having a second propellant source having dimensions defining a second stage discharge length, wherein the first stage discharge length is less than the second stage discharge length; and an ignition source for generating an ignition discharge across the first stage discharge length, wherein the first and second stages are designed such that an ignition discharge across the first discharge length initiates a subsequent ignition discharge across the second discharge length.
- 2. The propellant module as described in claim 1, further comprising a passive impedance source designed to transmit the ignition discharge current from the first stage propellant source to the second stage propellant source.
- 3. The propellant module as described in claim 1, wherein the ignition source includes a power supply in electrical communication with at least one ignition electrode.
- 4. The propellant module as described in claim 3, further comprising a switch for connecting or disconnecting the electrical communication between the power supply and the at least one ignition electrode.
- 5. The propellant module as described in claim 1, wherein the ignition source comprises:
a power supply; a first ignition electrode in electrical communication with the power supply; a second ignition electrode, wherein, the first stage propellant source is disposed between the first and second ignition electrodes; and a third ignition electrode, wherein the second stage propellant source is disposed between the second and third ignition electrodes.
- 6. The propellant module as described in claim 5, wherein the first, second and third ignition electrodes are cylindrical and arranged in a coaxial geometry.
- 7. The propellant module as described in claim 5, wherein the first and second propellant sources are made of a non-conductive material.
- 8. The propellant module as described in claim 5, wherein the electrodes are made of a conducting metal.
- 9. The propellant module as described in claim 5, further comprising at least two propellant rods.
- 10. The propellant module as described in claim 5, further comprising a passive impedance in electrical communication between the first and second stage, wherein the passive impedance transfers the ignition discharge from the first stage to the second stage.
- 11. The propellant module as described in claim 5, further comprising a switch in electrical communication between the first and second stage for triggering the ignition discharge of the second stage.
- 12. The propellant module as described in claim 5, further comprising a trigger capacitor in electrical communication with the ignition source, wherein the trigger capacitor provides an additional quantum of discharge energy to the ignition discharge across the first stage propellant source.
- 13. The propellant module as described in claim 5, further comprising an RC circuit in electrical communication with the first stage, wherein the RC circuit impedes the voltage rise on the first stage and controls the firing frequency of the propellant module.
- 14. The propellant module as described in claim 1, wherein the first and second stages comprise independent cylinders arranged in an adjacent relationship.
- 15. The propellant module as described in claim 14, wherein the first stage includes:
a first ignition electrode in electrical communication with a power supply, and a second ignition electrode, wherein the first stage propellant source is disposed between the first and second ignition electrodes; and wherein the second stage includes: a third ignition electrode in electrical communication with the second ignition electrode, and a fourth ignition electrode, wherein the second stage propellant source is disposed between the third and fourth ignition electrodes.
- 16. The propellant module as described in claim 15, wherein the first and second electrodes are arranged in a coaxial geometry and form a first propellant cylinder, and wherein the third and fourth electrodes are arranged in a coaxial geometry and form a second propellant cylinder.
- 17. The propellant module as described in claim 14, wherein the first and second propellant sources are made of Teflon.
- 18. The propellant module as described in claim 14, wherein the electrodes are made of a conducting metal.
- 19. The propellant module as described in claim 14, further comprising a passive impedance in electrical communication between the first and second stage, wherein the passive impedance transfers the ignition discharge from the first stage to the second stage.
- 20. The propellant module as described in claim 14, further comprising a switch in electrical communication between the first and second stage for triggering the ignition discharge of the second stage.
- 21. The propellant module as described in claim 14, further comprising a trigger capacitor in electrical communication with the ignition source, wherein the trigger capacitor provides an additional quantum of discharge energy to the ignition discharge across the first stage propellant source.
- 22. The propellant module as described in claim 14, further comprising an RC circuit in electrical communication with the first stage, wherein the RC circuit impedes the voltage rise on the first stage and controls the firing frequency of the propellant module.
- 23. The propellant module as described in claim 14, further comprising at least two second stages.
- 24. The propellant module as described in claim 23, further comprising a selector switch in electrical communication with the ignition source, wherein the selector switch determines which of the at least two second stages is ignited by the ignition discharge of the first stage.
- 25. A pulsed plasma thruster propellant module comprising:
a power source for generating an ignition voltage; at least two propellant rods in electrical communication with the power source, the at least two propellant rods including:
a first electrode, a second electrode, and a propellant source disposed between the first and second electrodes having dimensions defining a discharge length; and application of the ignition voltage to one of the at least two propellant rods generate an ignition discharge across the discharge length.
- 26. The propellant module as described in claim 25, wherein the ignition discharge is triggered by a triggering technique selected from the group consisting of: self-triggered, triggered, and quasi-steady.
- 27. The propellant module of claim 25 wherein each of the at least two propellant rods are designed to enter an open-circuit condition such that no further ignition discharges occur across said discharge length once the propellant source has been expended.
- 28. The propellant module of claim 25 wherein each of the at least two propellant rods further comprises an insulating tube surrounding one end of the first electrode such that when the propellant source has been depleted sufficiently to expose the insulating tube an open-circuit condition is entered such that no further ignition discharges occur across the discharge length.
- 29. The propellant module of claim 25 wherein each of the at least two propellant rods further comprises a non-ablative material disposed between the first and second electrodes at one end of the propellant rod such that when the propellant source has been depleted sufficiently to expose the non-ablative material an open-circuit condition is entered such that no further ignition discharges occur across the discharge length.
- 30. The propellant module of claim 25 wherein the discharge length between the first and second electrodes of each of the at least two propellant rods increases at one end of the propellant rod such that when the propellant source has been depleted sufficiently to reach the increased discharge length an open-circuit condition, is entered such that no further ignition discharges occur across said increased discharge length.
- 31. The propellant module as described in claim 25, further comprising a propellant rod switch for directing the ignition voltage between the at least two propellant modules.
- 32. A propulsion unit comprising the propellant module described in claim 1.
- 33. A propulsion unit comprising the propellant module described in claim 5.
- 34. A propulsion unit comprising the propellant module described in claim 14.
- 35. A propulsion unit comprising the propellant module described in claim 25.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority on U.S. provisional application No. 60/304,219 filed on Jul. 9, 2001, the content of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] The U.S. Government has certain rights in this invention pursuant to SBIR Contract No. F04611-00-C-0020, awarded by the Air Force Research Laboratory, Propulsion Directorate, Edwards AFB, Calif.
Provisional Applications (1)
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Number |
Date |
Country |
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60304219 |
Jul 2001 |
US |