Arcjet propulsion systems for spacecraft

Patent metadata

Field	Value
Publication number	US-10287036-B2
Application number	US-201615206181-A
Country	US
Kind code	B2
Filing date	Jul 8, 2016
Priority date	Jul 8, 2016
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

An arcjet thruster system for a spacecraft is provided. The arcjet thruster system may include a power supply that includes a radio-frequency start power supply and a continuous direct-current power supply, each selectively coupled to electrodes of an arcjet for initiation and maintenance of an arc between the electrodes. A radio-frequency/direct-current control module may be provided for selectively coupling the radio-frequency start power supply and a continuous direct-current power supply. The radio-frequency start power supply may be used to initiate an arc that is then sustained by the continuous direct-current power supply.

First claim

What is claimed is:

1. An arcjet thruster for a spacecraft, the arcjet thruster comprising:
an arcjet having:
an anode,
a cathode, and
a propellant valve configured to direct a propellant between the cathode and the anode; and

a power module comprising:
a radio-frequency start power supply,
a direct-current continuous power supply, and
a radio-frequency/direct-current control module coupled to the arcjet, the radio-frequency start power supply, and the direct-current continuous power supply,

wherein the radio-frequency/direct-current control module is (i) switchably coupled, at an input end, to the radio-frequency start power supply and the direct-current continuous power supply, (ii) coupled, at an output end, to a coaxial feedline for the arcjet, and (iii) is configured to provide a radio-frequency signal from the radio-frequency start power supply, via the coaxial feedline, to the cathode and the anode of the arcjet to initiate an electrical discharge arc between the anode and the cathode,
wherein the radio-frequency/direct-current control module is further configured to provide a direct-current voltage difference from the direct-current continuous power supply, via the coaxial feedline, to the cathode and the anode of the arcjet to sustain the electrical discharge arc, and
wherein the radio-frequency/direct-current control module is programmed with instructions to provide the direct-current voltage difference before the radio-frequency signal.

2. The arcjet thruster of claim 1 , wherein the radio-frequency/direct-current control module is configured to provide the direct-current voltage difference after the radio-frequency signal.

3. The arcjet thruster of claim 1 , wherein the direct-current voltage difference is less than 150 volts.

4. The arcjet thruster of claim 1 , wherein the radio-frequency signal has a frequency of at least one kilohertz.

5. A spacecraft, comprising:
a propulsion system that includes:
an arcjet having:
an anode,
a cathode, and
a propellant valve configured to direct a propellant between the cathode and the anode; and

a power module comprising:
a radio-frequency start power supply,
a direct-current continuous power supply, and
a radio-frequency/direct-current control module interposed between the arcjet and both of the radio-frequency start power supply and the direct-current continuous power supply,

wherein the radio-frequency/direct-current control module is configured to provide a radio-frequency signal from the radio-frequency start power supply to the arcjet via a coaxial feedline coupled to the radio-frequency/direct-current control module, the cathode, and the anode of the arcjet to initiate an electrical discharge arc between the anode and the cathode,
wherein the radio-frequency/direct-current control module is further configured to provide a direct-current voltage difference from the direct-current continuous power supply, via the coaxial feedline, to the cathode and the anode of the arcjet to sustain the electrical discharge arc,
wherein the radio-frequency/direct-current control module is programmed with instructions to provide the direct-current voltage difference before the radio-frequency signal.

6. The spacecraft of claim 5 , wherein the propulsion system comprises a plurality of arcjets.

7. The spacecraft of claim 5 , further comprising:
a body; and
at least one antenna mounted to an exterior surface of the body.

8. The spacecraft of claim 7 , wherein the arcjet is mounted in an opening in the spacecraft body, wherein the power module is disposed within the spacecraft body.

9. The spacecraft of claim 8 , further comprising a power generator for the spacecraft.

10. A method, comprising:
establishing a propellant flow between a cathode and an anode of an arcjet thruster;
providing a radio-frequency electrical signal to the cathode and the anode until an arc is generated between the cathode and the anode within the propellant flow;
providing a direct-current voltage difference between the cathode and the anode to maintain the arc; and
terminating the radio-frequency electrical signal while the direct-current voltage difference maintains the arc, wherein providing the direct-current voltage difference comprises providing the direct-current voltage difference before the arc is generated by the radio-frequency electrical signal.

11. The method of claim 10 , wherein the direct-current voltage difference is less than 150 Volts.

12. The method of claim 11 , wherein providing the radio-frequency electrical signal comprises providing the radio-frequency electrical signal at a frequency of at least one kilohertz.

13. The method of claim 10 , wherein providing the radio-frequency electrical signal comprises providing the radio-frequency electrical signal at a frequency of at least one kilohertz.

Assignees

• Lockheed Corp

Inventors

• LICHTIN Daniel Albert
• Blum Jacob H

Classifications

• F03H1/0006

  Details applicable to different types of plasma thrusters (arrangements specially adapted for fitting plasma engines in or to cosmonautic vehicles B64G1/413) · CPC title

• B64G1/42

  Arrangements or adaptations of power supply systems · CPC title

• B64G1/26

  using jets · CPC title

• B64G1/406 Primary

  Operations & Transport · mapped topic

• H05H1/54

  Plasma accelerators · CPC title