The NASA Two Dimensional Asymmetrical Capacitor Thruster
By Jean-Louis Naudin
created on November 18th, 2001 - JLN Labs - Last update November 19th, 2001
All informations in this page are published free and are intended for private/educational purposes and not for commercial applications

On November 13, 2001, the NASA patent US 6,317,310 " Apparatus and Method for generating a thrust using a two dimensional asymmetrical capacitor module " has been granted.

On the NASA TechFinder web site ( Public Release Date : Nov 6, 2001 ), we can read :
<< Objective : NASA scientists have discovered a method for generating thrust from two dimensional asymmetrical capacitor modules. The results are potentially greater efficiencies and improved reliability over currently available electric thrusters.
Description : In the past, inductive technology has been needed to create thrust, rotational motion, or step an actuator using electricity. This new technology accomplishes these tasks and more by using high potential, low current asymmetrical capacitor modules. The dielectric material of a capacitor under high voltage experiences a force. Based on the geometry of the capacitor, its material properties, and ambient conditions, the force can be predicted and utilized to move the entire capacitor and its mounting in a predictable direction. It had been theorized that thrust generation from this phenomenon was feasible, but no working prototypes had been developed, until now. >> ( Click here to read the full document )

United States Patent 6,317,310
Campbell November 13, 2001

Apparatus and method for generating thrust using a two dimensional, asymmetrical capacitor module


A capacitor module system is provided for creating a thrust force. The system includes a capacitor module provided with a first conductive element having a cylindrical geometry. The first conductive element can be a hollow cylinder or a solid cylinder. The capacitor module also includes a second conductive element axially spaced from the first conductive element and of smaller axial extent. The second conductive element can be a flat disk, a dome, or a conductive tip at the end of a dielectric rod. A dielectric element is disposed between the first conductive element and the second conductive element. The system also includes a high voltage source having first and second terminals connected respectively to the first and second conductive elements. The high voltage source applies a high voltage to the conductive elements of sufficient value to create a thrust force on the module inducing movement thereof.

This apparatus has been tested in June 2001 by Transdimensional Technologies in the vacuum chamber of the NASA Marshall Space Flight Center ( MSFC ) in Huntsville ( see the photo of the apparatus tested in vacuum by TdT )


Today, on November 18, 2001, I have fully replicated and tested successfully the NASA thruster experiment ( see the photo below ).

Tested apparatus description :

I have used the same design as described in the patent figure 2 : << Referring to FIG. 2, the module depicted, which is generally denoted 20, differs from that of FIG. 1 in that a simple cylindrical dielectric element 25 is positioned between conductive cylinder 22 and disk 24, instead of the cylindrical dielectric cylinder 15 and dielectric rods 16 employed in the embodiment of FIG. 1. >> ( see the photo below )

The two asymmetrical capacitors are made with a copper tube, a Polystyrene "Roofmat" cylinder for the dielectric and an aluminum disk.
The capacitors are fixed on a 440 mm diameter frictionless rotor, and the HV is sent through the main rotation axis.

The Two Dimensional Asymmetrical Capacitor Thruster specifications

Asymmetrical capacitor :

  • Main armature :
    - Copper tube ( 30 mm diam, 1mm thick and 40mm length ).

  • Dielectric :
    - A Polystyrene "
    Roofmat" cylinder block ( 32 mm diam and 33 mm length )

  • Secundary armature :
    - an aluminum disk 30 mm diam and 0.5 mm thick.

  • Weight : 40 g ( each )

  • Main rotor diameter : 440 mm

Material Dielectric constant ( K ) Dielectric Strength ( V/m )
Air 1.00059 3e6
Polystyrene 2.56 24e6
Kapton 4.2 11.8e7
Barium Strontium Titanate ( BaSrTiO3 ) 13800 10e7

Click here to se some construction details of the apparatus

TESTS RESULTS ( 11-18-01 ) :

When the HV power supply is switched on, the Two Dimensional Asymmetrical Capacitor Thruster begins to rotate and accelerates quickly to a high speed. The first test has been conducted with the basic 30 KV DC pulsed power supply that I have used for the Basic Lifter experiment. See the detailled diagram of this basic 30 KV power supply.

During some other tests conducted with an enhanced power supply, the average voltage measured was 24 KV DC and the current 51 uA at 10 KHz. All the parasitic leakage current has been removed by using insulated wires, so this explains the low value of the current required for getting the effect. The High Voltage Power required for a full speed rotation ( 65 RPM ) was only 1.22 Watts...

The test curve below has been done at 29 KV DC @ 60 uA ( 1.74 W ) :

See the video of Two Dimensional Asymmetrical Capacitor Thruster experiment

To see the videos, the free downloadable RealPlayer is required

Click on the picture above to see the video ( 846 Kb )

Documents references :

  • The Transdimensional Technologies web site

  • Read the NASA Patent description and see the FULL NASA PATENT US 6,317,310 ( granted November 13, 2001 )
    NASA MFS 31419_1 - Apparatus & Method for Generating Thrust Using a Two Dimensional, Asymmetrical Capacitor;

  • General Specification of KAPTON polyimide film by DuPont de Nemours and Company

  • E-Field gradient around the NASA's Two dimensional asymmetrical capacitor module by Vencislav Bujic

  • See also :

    The ACT Working principle proposal by JL Naudin

    The Asymmetrical Capacitor Thruster v2.0

    The Asymmetrical Capacitor Thruster v3.0

    Email :

    Return to the Lifters experiments page