Gustave C. Fralick

Glenn Research Center, Cleveland, Ohio

Janis M. Niedra

QSS Group, Inc., Brook Park, Ohio

Experimental Results of Schlicher’s

Thrusting Antenna

NASA/TM—2001-211207

November 2001

AIAA–2001–3657
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Prepared for the

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cosponsored by the AIAA, SAE, AIChE, and ASME

Salt Lake City, Utah, July 8–11, 2001

Gustave C. Fralick

Glenn Research Center, Cleveland, Ohio

Janis M. Niedra

QSS Group, Inc., Brook Park, Ohio

Experimental Results of Schlicher’s

Thrusting Antenna

NASA/TM—2001-211207 AIAA–2001–3657
Acknowledgments

The authors would like to thank Carl Lorenzo and Ken Weiland, who constructed the antenna, John Wrbanek, who

helped with the figures, and Dr. Norm Wenger, who contributed to the analysis.

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NASA/TM—2001-211207 1 

EXPERIMENTAL RESULTS OF SCHLICHER’S THRUSTING ANTENNA 

Gustave C. Fralick 

National Aeronautics and Space Administration 

Glenn Research Center 

Cleveland, Ohio 44135 

Janis M. Niedra 

QSS Group, Inc. 

Brook Park, Ohio 44142 

Abstract

Experiments were conducted to test the claims by Rex 

L. Schlicher et.al. (Patent 5,142,861) that a certain 

antenna geometry produces thrust greatly exceeding 

radiation reaction, when driven by repetitive, fast rise 

and relatively slower decay current pulses. In order to 

test this hypothesis, the antenna was suspended by 

strings as a 3 m pendulum. Current pulses were fed to 

the antenna along the suspension path by a very flexible 

coaxial line constructed from loudspeaker cable and 

copper braid sheath. When driving the antenna via this 

cabling, our pulser was capable of sustaining 1200 A 

pulses at a rate of 30 per second up to a minute. In this 

way, bursts of pulses could be delivered in synch with 

the pendulum period in order to build up any motion. 

However, when using a laser beam passing through a 

lens attached to the antenna to amplify linear 

displacement by a factor of at least 25, no correlated 

motion of the beam spot could be detected on a distant 

wall. We conclude, in agreement with the momentum 

theorem of classical electromagnetic theory, that any 

thrust produced is far below practically useful levels. 

Hence within classical electrodynamics, there is little 

hope of detecting any low level motion that cannot be 

explained by interactions with surrounding structural 

steel and the Earth’s magnetic field. 

Introduction

This paper describes the attempt to measure the thrust 

of the “Non-Linear Electromagnetic Propulsion 

System” (NEMPS), patent no. 5,142,861, (Ref. 1) and 

described at the 31st Joint Propulsion Conference (Refs. 

2-5). The device supposedly generates a mechanical 

force when electric current is sent through it. Such a 

device, if it produced more than the miniscule thrust of 

a photon rocket, would be a boon for deep space, 

perhaps, even interstellar, missions. No longer would it 

be necessary to carry half the mass of the mission in 

fuel. Just connect your electric thruster to a power 

source, such as a radioisotope heat source, and off you 

are to the nearest star! 

After an attempt to acquire a thruster from the 

developer, we decided to build our own, using the 

patent drawings and other published material (Refs. 

1-5) as construction guidelines. We also built our own 

pulse power supply, again relying on the sketchy 

descriptions provided in the references. Since we 

received no direct help from the developer, the device is 

not a perfect reproduction, but likely works as well. The 

reasons for this statement are given at the end of this 

paper. 

Principle of Operation of the NEMPS thruster

According to the device description given in Ref. 2, 

“the rigid three dimensional geometric asymmetries in 

the loop antenna structure cause a magnetic field 

density gradient internal to the antenna structure along a 

single axis. This magnetic field density gradient then 

causes an imbalance in the internal magneticmechanical forces that normally result from the 

interactions of the loop antenna’s internal magnetic 

field with the current in the conductors of the loop 

antenna’s structure, as described by the Lorentz force 

law.” The thruster is powered by a pulsed power supply 

“designed to provide the proper waveform to the 

antenna structure at an impedance matching the load 

impedance of the antenna. The rise time and shape of 

the input current waveform is crucial to maximizing the 

production of reaction thrust.” However, neither the 

pulse parameters nor the reason for their criticality are 

given. 

Description of Experiment

Conducting the experimental test of the claims of the 

NEMPS thruster turned out to present a different set of 

problems than was expected. Initially we thought that 

we would see evidence of some force being produced, 

and then have to eliminate any spurious or non-relevant 

forces, such as interaction with the earth’s magnetic 

field, or with the structural steel of the building, or 

perhaps even the electrostatic precipitator effect. But 

we really observed no evidence of any force 
NASA/TM—2001-211207 2 

whatsoever. Thus we were reduced to setting an upper 

limit for the force produced by the thruster. 

The first step in testing the NEMPS thruster was to 

build it. As can be seen from the drawing, (Fig. 1), and 

our implementation of it (Fig. 2) the device is a coaxial 

transmission line, the outer conductor of which blooms 

into a petal like arrangement. Four bundles of two 

conductors each lead from the petals back to the center 

conductor to complete the circuit. In our embodiment of 

the NEMPS thruster, the center conductor is a piece of 

copper rod, 1/4” in diameter and 30” long. The portion 

of the outer conductor between the input and the petals 

is a piece of copper pipe, 11

/2” in diameter. The distance 

from the petals to the input is 5 1

/2”. The petals, there 

are eight of them, are made of 1/8” aluminum plate. 

They fan out at an angle of approximately 45 degrees to 

a diameter of 6”, and then are parallel to the central axis 

for another 23

/4”. The four conductor bundles run 

parallel to the axis for 10”, then back to the center 

conductor at an angle of 50 degrees. The mass of the 

thruster is approximately 1.8 kg. 

The second step in testing the thruster was to provide 

power to it. The power is fed through a pair of 14 gauge 

wires, surrounded with copper braid, effectively making 

a high current coaxial cable. 

The shape of a typical current pulse when operating 

into a 0.05 Ω resistive load is shown in Fig. 3. Here the 

pulse height is 2400 A, with rise and fall times of about 

13 μs and 314 μs, respectively. However, when driving 

the thruster via our made-up coaxial cables, the 

amplitude was reduced by the increased impedance to 

about 1200 amps peak, and the rise and fall times 

increased to about 20 μs and 400 μs, respectively. The 

pulse repetition rate was 30 pulses per second. To the 

best of our ability, we duplicated the pulse shape shown 

in Fig. 4, which is a sketch from Ref. 1. 

This brings us to actually measuring the force. After 

considering various schemes, we decided to hang the 

thruster as a pendulum. This provides a low friction 

mount, and a convenient means for measuring the force. 

Any force produced by the thruster produces a 

displacement from its equilibrium position d=L (F/W), 

where L is the pendulum length, F is the force 

produced, and W is the thruster’s weight. 

In order to increase our ability to detect any motion of 

the thruster, a simple lens (focal length = 4”) was 

attached to the thruster, and the beam from a small laser 

was passed through the lens and onto an opposite wall. 

The displacement of the spot on the wall, D, is related 

to the thruster displacement d, by the relation D = 

(R/f) d, where R is the distance from the lens to the wall 

and f is the focal length of the lens. In our case R = 9’4”

and f = 4”, so the magnification factor R/f = 28. 

With this setup, we could estimate the upper limit for 

the thrust produced by the antenna. Occasianally there 

was spot displacement of perhaps a centimeter upon 

initial energizing of the thruster. It was not repeatable 

during a test session, and we attributed it to momentary 

stiffening of the power cable. The power supply was 

equipped with a switch that allowed us to apply power 

to the thruster in bursts. We tried to apply power at the 

natural frequency of the pendulum, in hope of seeing a 

greater displacement, but to no avail. 

Thus we (generously) take the maximum observable 

spot displacement as 1 cm. This translates to a 

pendulum displacement of (10−2

 m)/28 = 3.6x10−4 m. 

The length of the pendulum was 88” = 2.2 m, so the 

ratio d/L is (3.6x10−4

 m)/(2.2 m) = 1.6x10−4. The 

weight of the thruster is 1.8 kg x 9.8 ms−2

 = 17.6 

newtons, so the upper limit for the thruster force is 

17.6 N x 1.6x10−4

 = 2.8x10−3 N = 6.3x10−4 lbf = 

1.0x10−2 ozf. This is considerably less than the force 

expected by the authors: 0.03 to 0.3 N at 4 amps, 

28 volt dc. (Ref. 5). But, in a sense, the amount of 

thrust produced by this device is irrelevant to spacecraft 

propulsion. That is the topic of the next section. 

Is There Hope for a Space Drive Within Classical

Electrodynamics?

We should recognize, and the earlier the better, that 

there is little hope for a propulsion scheme that appears 

as a space reaction drive to an external inertial observer 

and is based only on the exceedingly well established 

Maxwellian electrodynamics. The heart of the matter is 

that classical electrodynamics and mechanics requires 

conservation of momentum in flat spacetime. Without 

the existence of an ether-like medium that could sustain 

volume forces, the momentum of an isolated 

electrodynamic system (matter plus the EM fields it 

generates) is strictly conserved. And of course, 

Maxwell’s equations are incompatible with that kind of 

ether. Thus a scheme based on classical concepts can be 

at most a photon rocket. 

Since space reaction schemes based just on EM fields 

keep being proposed, it may be worthwhile to review 

the derivation of the EM momentum theorem in order 

to appreciate its compelling nature. Taking the 

macroscopic view of material properties, formal 
NASA/TM—2001-211207 3 

manipulation of Maxwell’s equations leads to the 

divergence relation 

)BD( t BJET &&&&&(

× ∂

∂ =⋅∇ ρ +×+ , 

where 

I)BHDE( 2

1 BHDET (&&&&&&&&( ⋅+⋅−+≡

is the Maxwell stress tensor (in dyadic notation). This 

form of T

(

 neglects the various internal stresses in 

matter, due to magneto- and electro-striction and 

nonuniformity of polarizabilities; however, these terms 

do not contribute to the volume integral of T(

⋅∇ . 

Although the terms in the T(

⋅∇ have the dimensions of 

force density and v BJEF

&&&& ≡ ρ ×+ is clearly the usual 

Lorentz force density on matter, nothing in the 

derivation requires that every term in T(

⋅∇ be 

interpreted as a force density. Forcing such an 

interpretation on )BD( t

&&

× ∂

∂ suggests the dubious 

notion of a force on EM fields or even space itself! It 

may be best to avoid such interpretations, with their 

ether-like notions, and to proceed with the integration 

leading to the momentum theorem, as per standard 

textbooks in electrodynamics (Ref. 6). The physical 

interpretation is then thrown back to well established 

concepts. Under the assumption that the Lorentz force 

is the only force on the matter in our electrodynamic 

system, the rate of change of its mechanical momentum 

is just 

∫∫∫ =

V

v dvF

dt

pd & &

, 

where the volume of integration V encloses the system. 

Hence in this notation, 

Tdv)BD(p nˆdA

dt

d

AV

∫∫∫∫∫  ⋅=



 





×+& (&& . 

Letting the surface A of V expand in all directions, the 

above surface integral vanishes rigorously. To see this, 

observe that the nonradiative components of the fields 

decay faster than 1/r with distance, thus contributing 

terms to n T ⋅ ˆ ( that decay faster than 1/r2

. And if the 

surface is sufficiently far away, then any radiative fields 

turned on at a finite time in the past have not yet 

reached the surface – all photons are caught within the 

surface and taken into account. The result is the wellknown, and relativistically valid, momentum theorem:

dv)BD(p =×+ const. ∫∫∫

∞

&& &

The above volume integral is easily interpreted as the 

total momentum in the EM field and for free space, the 

integrand reduces to the familiar 2 c/)HE( &&

× . 

This momentum conservation law clearly shows that 

from the point of view of classical mechanics, the 

validity of Maxwell’s equations in flat spacetime limits 

the space drive to at best a photon rocket. One might try 

to argue such things as what is the EM momentum in 

matter etc., but this is at the level of ‘tweaking’ and not 

a solution to practical interstellar transport. This severe 

bottom line strongly suggests that for practical, globally 

fast mass/energy transport, one must work around the 

classical limitations of momentum conservation by 

digging into the deeper layers of spacetime structure 

itself – the so called “spacetime engineering”. Quite 

likely, that will bring one to deal with the vacuum zeropoint fluctuations, the so-called virtual particle pairs 

and possibly other elements of the support of 

spacetime. 

Summary and conclusions

No reproducible evidence was ever seen for any thrust 

when current pulses of 1200 A peak and 20 μs risetime 

were applied to the antenna at a rate of 30 per second. 

The result was still null, even when bursts of these 

pulses were applied in synch with the period of the 

pendulum-like suspension of the antenna. Our 

experiment could detect a steady force as low as 3 mN. 

The simplicity and import of the electromagnetic 

momentum theorem underscore the hopelessness of any 

space reaction scheme strictly within classical 

electrodynamics. This severe bottom line strongly 

suggests that for practical, globally fast mass/energy 

transport, one must work around the classical 

limitations of momentum conservation by digging into 

the deeper layers of spacetime structure itself—the so 

called “spacetime engineering”. Quite likely, that will 

bring one to deal with the vacuum zero-point 

fluctuations, the so-called virtual particle pairs and 

possibly other elements of the support of spacetime. 
NASA/TM—2001-211207 4 

References

1. R. L. Schlicher, et al., United States Patent 

5,142,861, Nonlinear Electromagnetic Propulsion 

System and Method, Sept. 1, 1992 

2. R. L. Schlicher, et al., Nonlinear Electromagnetic 

Propulsion System and Method, 19th Power 

Modulation Symposium, IEEE, New York, 1990, 

pp. 139-145. 

3. R. L. Schlicher, A. W. Biggs, W. J. Tedeschi, 

Mechanical Propulsion from Unsymmetrical 

Magnetic Induction Fields, 31st

AIAA/ASME/SAE/ASEE Joint Propulsion 

Conference and Exhibit, AIAA 95-2643, July, 1995. 

4. R. L. Schlicher, A. W. Biggs, W. J. Tedeschi, 

”Antenna Geometry” Mechanical Propulsion from 

Unsymmetrical Magnetic Induction Fields, 31st

AIAA/ASME/SAE/ASEE Joint Propulsion 

Conference and Exhibit, July, 1995. 

5. R. L. Schlicher, A. W. Biggs, W. J. Tedeschi, 

“Theoretical Analysis”, Mechanical Propulsion 

from Unsymmetrical Magnetic Induction Fields, 31st

AIAA/ASME/SAE/ASEE Joint Propulsion 

Conference and Exhibit, July, 1995. 

6. W.K.H. Panofsky and M. Phillips, Classical 

Electricity and Magnetism, 2nd Edition, AddisonWesley Publishing Co., 1962. pp. 181-184. 
NASA/TM—2001-211207 5 

Figure 1. A typical NEMPS antenna, illustrated by R.L. Schlicher in his patent 5,142,861. 

Figure 2. Our rendition of a NEMPS antenna, suspended from the ceiling. The coaxial 

Cable for current feed is visible on the right. Note also the lens for detection 

of motion by means of a laser beam. 
NASA/TM—2001-211207 6 

Figure 3. Typical pulse shape at maximum capability: 2400 A peak into a 0.05 

resistive load. When driving the thruster antenna through our coaxial 

cable, the pulse height was reduced to about 1200 A, at rise and fall 

times of about 20 μ s and 400 μ s, respectively. 

Figure 4. Current pulse shape sketch shown in the Schlicher patent. No scales are given. 

Antenna Current Input

Time

Ω
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12

Experimental Results of Schlicher’s Thrusting Antenna

Gustave C. Fralick and Janis M. Niedra

Electromagnetic theory; Propulsion; Maxwell's equations

Unclassified -Unlimited

Subject Category: 07 Distribution: Nonstandard

Prepared for the 37th Joint Propulsion Conference and Exhibit cosponsored by the AIAA, SAE, AIChE, and ASME,

Salt Lake City, Utah, July 8–11, 2001. Gustave C. Fralick, NASA Glenn Research Center, and Janis M. Niedra,

QSS Group, Inc., 2000 Aerospace Parkway, Brook Park, Ohio 44142. Responsible person, Gustave C. Fralick,

organization code 5510, 216–433–3645.

Experiments were conducted to test the claims by Rex L. Schlicher, et al., (Patent 5,142,861) that a certain antenna

geometry produces thrust greatly exceeding radiation reaction, when driven by repetitive, fast rise, and relatively slower

decay current pulses. In order to test this hypothesis, the antenna was suspended by strings as a 3 m pendulum. Current

pulses were fed to the antenna along the suspension path by a very flexible coaxial line constructed from loudspeaker

cable and copper braid sheath. When driving the antenna via this cabling, our pulser was capable of sustaining 1200 A

pulses at a rate of 30 per second up to a minute. In this way, bursts of pulses could be delivered in synch with the

pendulum period in order to build up any motion. However, when using a laser beam passing through a lens attached to

the antenna to amplify linear displacement by a factor of at least 25, no correlated motion of the beam spot could be

detected on a distant wall. We conclude, in agreement with the momentum theorem of classical electromagnetic theory,

that any thrust produced is far below practically useful levels. Hence, within classical electrodynamics, there is little

hope of detecting any low level motion that cannot be explained by interactions with surrounding structural steel and the

Earth’s magnetic field.