The NASA Orbital Maneuvering Propellantless Thruster
OMPT v1.0 tests
By Jean-Louis Naudin
created on March 10, 2002 - JLN Labs - Last update March 30, 2004
All informations in this page are published free and are intended for private/educational purposes and not for commercial applications

On January 31, 2002, the NASA patent application US2002012221 " 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.
Potential Application(s)
- Linear accelerator to launch payloads
- Rotate a propeller or other shaft driven application
- Stepping actuator
Near-earth orbital maneuvering >> ( Click here to read the full TOPS document on the NASA web site )

The NASA US PATENT : US6411493 ( June 25, 2002 )

Apparatus for generating thrust using a two dimensional, asymmetrical capacitor module
Patent Number: US6411493B2
Publication date:   2002-06-25
Inventor(s):    CAMPBELL JONATHAN W (US)
Applicant(s):  US OF AMERICA NASA (US)

Abstract : An asymmetrical capacitor module for generating thrust includes two conductive elements of similar but different geometries separated by a dielectric member. Improved embodiments provided in the construction of conductive elements of smaller axial extent include those where the element is formed by an annular wire or a dielectric supported ring. Other embodiments concern the dielectric member and involve changes in the extent and shape thereof. 

This patent application is the following of the NASA patent US 6,317,310 ( granted November 13, 2001 ) from Jonathan Campbell.


On March 10, 2002, I have built and tested successfully the NASA electric thruster ( see the photo below ).

Tested apparatus description :

I have used the same design as described in the patent figure 8 and described at page 3 [0043]: << Yet another embodiment of the invention is shown in FIG.8, wherein the same numbering scheme is used. In this embodiment, a dielectric sleeve or body (80) of a frustroconical configuration is employed. A rear conductor (82) is provided by a conducting surface on a less severely tapered portion of body (80). A separate front (84) conductor 84 is also formed by a conducting surface or coating and is also of frustroconical shape. A central dielectric strut or post (86) supports front conductor (84)>> ( see the diagram below )

The two OMPTs are fixed on a 440 mm diameter frictionless rotor, and the HV is sent through the main rotation axis.

TESTS RUN #1 ( 03-10-02 ) :

When the HV power supply is switched on, the OMPT v1.0 begins to rotate and accelerates quickly to a high speed. This confirms fully the claim of the inventor. The voltage used during the test was 45.7 KV at 1.02 mA.

See the video of the Orbital Maneuvering Propellantless Thruster experiment

To see the videos, the free downloadable RealPlayer is required

Click on the picture above to see the video ( 440 Kb )

TESTS RUN #2 ( 03-12-02 ) :

The purpose of this test is to reduce the parasitic leakage current in the device. So, I have covered the edge of the rear armature (82) with a High Voltage insulation tape. When the High Voltage ( 45.7 KV ) is sent, the device rotates quickly with the same turn speed than the test RUN #1 and the current has dropped to 0.6 mA. This test confirms also that the thrust observed is not the result of the ejection of electrons backward.

See the video of the OMPT v1.0 test RUN #2

To see the videos, the free downloadable RealPlayer is required

Click on the picture above to see the video ( 294 Kb )

Vacuum ranges

Vacuum classes corresponding pressure ranges :

Documents references :

  • NASA patent application US6411493 " Apparatus and Method for generating a thrust using a two dimensional asymmetrical capacitor module " ( granted June 25, 2002 )

  • 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 Goodfellow

  • NASA Technology Opportunity - TOPS ( 11-06-01 )

  • See also :

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