Propellant tank and loading for electrospray thruster

Patent metadata

Field	Value
Publication number	US-10308377-B2
Application number	US-201514681264-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	May 3, 2011
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

Methods and apparatus of adding propellant to a thruster assembly are described. A first end of a beaker is disposed in an opening of the tank, where the beaker contains propellant and the first end of the beaker includes a breakaway bottom. The thruster assembly and beaker are placed in a first environment, where the first environment is substantially a vacuum and/or an environment composed substantially of gases that can be absorbed by the propellant. A plunger in the beaker is depressed to cause the breakaway bottom of the beaker to break and the propellant to flow into the tank of the thruster assembly. The thruster assembly is removed from the first environment and the beaker is removed from the opening. A cap is added to complete the assembly. The assembly contains a vent to allow gases to escape the interior of the tank.

First claim

What is claimed is:

1. A method of adding propellant to a thruster assembly, wherein the thruster assembly comprises a tank comprising a first opening and a second opening;
a porous emitter array disposed over the first opening;
a porous reservoir disposed within an interior of the tank, wherein the porous reservoir is in fluid communication with the porous emitter array through the first opening, the method comprising:
disposing a first end of a beaker in the second opening of the tank, wherein the beaker contains the propellant, and wherein the first end of the beaker comprises a breakaway bottom;
placing the thruster assembly and beaker in a first environment, wherein the first environment is at least one of a vacuum or an environment composed of gases that can be absorbed by the propellant;
depressing a plunger in the beaker to cause the breakaway bottom of the beaker to break and cause the propellant to flow into the tank;
removing the thruster assembly from the first environment; and
removing the beaker from the second opening.

2. The method of claim 1 , further comprising:
affixing a cap to the second opening of the tank.

3. The method of claim 2 , wherein the cap comprises a porous membrane that permits gas to pass therethrough and blocks the propellant from passing therethrough.

4. The method of claim 3 , wherein first pores of the porous membrane are larger than second pores of the porous emitter array.

5. The method of claim 3 , wherein the porous membrane is made from at least one of polytetrafluoroethylene, PEEK and polyethylene.

6. The method of claim 1 , wherein the tank comprises a porous membrane that permits gas to pass therethrough and blocks the propellant from passing therethrough.

7. The method of claim 1 , further comprising:
extending the plunger into the tank to compress the porous reservoir, thereby at least partially submerging the porous reservoir in the propellant; and
retracting the plunger from the tank.

8. An assembly comprising:
a thruster assembly comprising:
a tank comprising a first opening and a second opening;
a porous emitter array disposed over the first opening; and
a porous reservoir disposed within an interior of the tank,

wherein the porous reservoir is in fluid communication with the porous emitter array through the first opening;
a beaker having a first end comprising a breakaway bottom, wherein the first end of the beaker is disposed in the second opening,
wherein prior to the breakaway bottom breaking, liquid propellant is retained in the beaker, and wherein when the breakaway bottom breaks, the liquid propellant flows into the tank.

9. The assembly of claim 8 , wherein the beaker is filled with the liquid propellant, the assembly further comprising:
a plunger disposed in the beaker to cause the breakaway bottom of the beaker to break and cause the liquid propellant to flow into the tank when depressed.

10. The assembly of claim 8 , wherein the beaker is selectively removable from the second opening.

11. The assembly of claim 8 , wherein the breakaway bottom is constructed and arranged such that when the breakaway bottom is broken, the beaker is removable from the second opening.

12. The assembly of claim 8 , wherein the beaker is filled with liquid propellant disposed between the second opening and a plunger, and wherein the plunger is depressible toward the second opening.

13. The assembly of claim 8 , wherein the porous reservoir is adapted to transport the liquid propellant to the porous emitter array through capillarity.

14. A thruster assembly comprising:
a tank comprising a first opening and a vent;
a porous emitter array disposed over the first opening;
a porous reservoir disposed within an interior of the tank, wherein the porous reservoir is in fluid communication with the porous emitter array through the first opening; and
a liquid propellant disposed within the porous reservoir, wherein the vent comprises a porous membrane that permits gas to pass therethrough and blocks the liquid propellant from passing therethrough.

15. The thruster assembly of claim 14 , wherein first pores of the porous membrane are larger than second pores of the porous emitter array.

16. The thruster assembly of claim 14 , wherein the porous membrane is made from at least one of polytetrafluoroethylene, PEEK and polyethylene.

17. A thruster assembly comprising:
a tank comprising a first opening, wherein the tank is formed from one or more semi-permeable materials that permits gas to pass therethrough and blocks a liquid propellant from passing therethrough;
a porous emitter array disposed over the first opening;
a porous reservoir disposed within an interior of the tank, wherein the porous reservoir is in fluid communication with the porous emitter array through the first opening; and
the liquid propellant disposed within the porous reservoir.

18. The thruster assembly of claim 17 , wherein first pores of the tank are larger than second pores of the porous emitter array.

19. The thruster assembly of claim 17 , wherein the tank is formed from at least one of porous polytetrafluoroethylene (PTFE) and hydrophobic solgel.

20. The thruster assembly of claim 17 , further comprising:
a propellant container disposed within the interior of the tank, wherein the propellant container is formed from another one or more semi-permeable materials that permit gas to pass therethrough and block the liquid propellant from passing therethrough; and
wherein the porous reservoir is disposed within an interior of the propellant container.

21. The thruster assembly of claim 20 , wherein first pores of the propellant container are larger than second pores of the porous emitter array.

22. The thruster assembly of claim 21 , wherein the propellant container is formed from at least one of porous polytetrafluoroethylene and hydrophobic solgel.

23. The assembly of claim 12 , wherein depressing the plunger toward the second opening causes the liquid propellant to flow into the tank.

Assignees

• Massachusetts Inst Technology

Inventors

• Lozano Paulo C
• Fucetola Corey Patrick

Classifications

• F03H1/0012 Primary

  Means for supplying the propellant · CPC title

• B64G1/405 Primary

  Operations & Transport · mapped topic

• B64G1/413

  Ion or plasma engines · CPC title