SPR Ltd 1

The EmDrive - A New concept in Spacecraft Propulsion

Roger Shawyer C.Eng MIET FRAeS

SPR Ltd September 2008

www.emdrive.com

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HOTBIRD 2 Launch (Nov 1996)

Total vehicle mass at launch 204 tonnes

Satellite mass on station 1.3 tonnes

Majority of mass lost is reaction mass

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EmDrive

EmDrive is the first

technology to provide

direct conversion of

electrical energy to

thrust, without the need

for reaction mass, and

without contravening the

laws of physics

Prototype C Band Thruster

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Why Launch satellites?

Fear Military applications e.g. NATO 1VB

Greed Commercial applications e.g. HOTBIRD 2

Curiosity Scientific missions e.g. SMART 1

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Benefits of Propulsion without reaction mass

Military - Increase in manoeuvrability

No residual propellant limitation

Commercial - Lower launch costs

Longer operating lifetime

Scientific - Shorter mission times

Larger payloads

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Principle of Operation

Electromagnetic waves carry momentum

Newton’s 2nd Law

Force = Rate of change of momentum

Radiation pressure proportional to propagation velocity

Propagation velocity dependent on Waveguide geometry

Waveguide resonant at input frequency

Force difference multiplied by Q

Einstein’s Law of Special Relativity

EM wave and waveguide have different frames of reference

EmDrive is an Open System

F2

F1

Magnetron

T = Q(F1-F2)

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Production of net thrust

Guide Wavelength for Circular TM01 at 2GHz

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5500

0 50 100 150 200 250 300 350 400 450 500

Waveguide Diam eter (m m )

Gu

ide

wav

elen

gth

(m

m)

F1 F2

F3

Area A1 Area A3

Area A2

Propagation velocity has a highly non linear relationship with waveguide diameter

At cut off diameter,velocity is zero, F2 is zero, but A2 is clearly not zero.

Sidewall thrust F3 does not equal F1

A net force in the direction of F1 is produced

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Conservation of Momentum

F2 F1

Reaction Force

F=Ma

Thrust

T=Q(F1-F2)

Total Momentum gained by thruster =Q x Momentum lost by EM wave at each reflection

Mechanical reaction occurs between thruster end plates and EM wave

Electrical reaction occurs as input impedance changes with acceleration

EmDrive is a true electrical machine

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Conservation of Energy

Q = Stored energy/energy lost per cycle

Acceleration extracts stored energy from the thruster

Thus acceleration reduces Q

Loss of Q increases with average velocity

Effect of increased Q

For Q= 5x104 (1st generation EmDrive)

Static specific thrust =315mN/kW

Specific thrust at 3 km/s = 200mN/kw

For Q = 5x109 (superconducting)

Static specific thrust = 31.5 kN/kW

Specific thrust at 0.1 m/s = 8.8 kN/kW

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Experimental Programme

2001 DTI SMART Award Experimental Thruster

2002 Proof of Concept

2003 DTI R&D Grant awarded Demonstrator Engine

2007 Demonstrator Engine tests complete

2008 Superconducting Thruster tests start

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Experimental Thruster Demonstrator Engine ( 2002) (2006)

Static specific thrust = 19mN/kW Static specific thrust = 214mN/kW

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Measurement methods

Design software verified by small signal measurement of frequency and Q

Static Thrust measured in Vertical Up,Vertical Down and Horizontal configurations

Proof of concept test programme eliminated all proposed spurious force mechanisms

Pulse tests proved momentum exchange

Thrust, Power and Temperature data recorded for each test run

All measurement parameters regularly calibrated

Test rigs subject to EMC testing

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Dynamic Test Rig (2007) Acceleration of 100kg beam supported on air bearing to 2 cm/s

Dynamic specific thrust = 287mN/kW

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Dynamic Test Programme

Direction of acceleration confirms that EmDrive obeys Newtons Laws

EmDrive is not a reactionless machine

Input power telemetry confirms electrical reaction during acceleration

Acceleration only starts as input frequency locks to resonant frequency

Programme included acceleration and deceleration runs in both directions

Calibration to determine friction torque carried out prior to each test run

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Applications

C Band Flight Engine Data compared to US I on engine

NSTAR I on Thruster C Band Flight EmDrive

Thrust 92mN 85 mN

DC I nput Power 2,310W 450W

Mass Flow 2.86 mg/ sec Zero

Overall Dimensions

331 mm 389 mm 508 mm (plus propellant subsystem)

170 mm 220 mm 240 mm

Total Mass 31 kg (plus propellant subsystem)

6.7 kg

Note EmDrive design based on a 3.9GHz flight thruster powered by 2 x 150W TWTAs. (Static specific thrust 283 mN/ kW)

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Typical Commsat Application

3 tonne GEO communications satellite contains 1.7 tonnes of propellant

Launch mass reduced to 1.3 tonnes

Cost savings £15 billion for GEO launches planned for next 10 years

Deployment of solar arrays and antennas in LEO

Spiral trajectory (Edelbaum transfer) to GEO in 36 days

Operational life no longer restricted by propellant reserves

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Science Mission Applications

Comparison with SNECMA PPS1350 system performance for ESA SMART 1 Luna Probe mission

Performance Parameter Current Ion Propulsion System

Proposed EmDrive System

DC power (Watts) Thrust (mN) Thrust period (Years) System Mass (kg)

1500 92 0.5

112.5

1500 283 15 9

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The Future

Large geostationary communications satellites

- In orbit mass > 20 tonnes

- Global mobile telephone system capability

- Will replace terrestrial mobile phone systems

Solar Power Satellites

- LEO to GEO transfer using EmDrive engines operating at

downlink frequency

- EmDrive is an enabling technology for SPS

- Provides a secure green solution to the global energy problem

Manned Mars missions - Solar powered UHF EmDrive engines

- Short flight times (41 days)

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Second Generation Engines

Superconducting technology can give thrust increase x 105

Superconducting cavities in production for high energy physics experiments

e.g. Q=2x109 for LHC at CERN and 5x109 for TESLA test facility

Engine used for static thrust space applications e.g.asteroid deflection

- Thrust orthogonal to asteroid velocity

- 1 kW second generation engine

- Nuclear power source 24 kW

- 1 Km diameter asteroid deflected 300,000 Km over 10 years

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Superconducting Lift Engines

Use as lift engine to counteract gravity.Liquid hydrogen cooling

Conventional propulsion for vehicle acceleration.Hydrogen fuelled

Hybrid reusable launch vehicle -260 tonne launch vehicle

- Four 22 kW lift engines - 1 tonne thrust ascent rocket engine - 50 tonne thrust orbital rocket engine

- 20 tonnes payload to LEO - Vehicle shape optimised for re-entry

- Vertical landing

Terrestrial transport

- A major incentive to change to a hydrogen based economy

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Status of current programmes

US Programme

Visit to major US aerospace company made in Sept 2006

Subsequent transfer of basic theoretical and experimental results (all now available in Public Domain)

Request for export licence made by US, based on an End User Undertaking for a military flight demonstrator programme

Export licence granted by UK January 2008

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Programme in China

1991 First UK patent published

1994 First Chinese patent published

2006 Initial contacts made by Chinese industry

2007 NWPU programme started at Xian

April 2008 Visit to Xian University

August 2008 Initial NWPU simulation results provided

Current activities include manufacture of large S Band thruster

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SPR Current Programmes

Flight Model programme Equipment specification issued

Initial design work completed Development started

Demonstrator satellite proposal 100kg 100W microsatellite

LEO satellite inspection missionContinuous manoeuvring in LEOLEO to GEO transfer after10 monthsEarth escape after 3 yearsTerminal vel 16.5km/sec after 7yrs

Design study for 2nd Generation Demonstrator vehicle

Uses four 3kW lift engines cooled by liquid hydrogen

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Feasibility Study for 2nd generation engine

Experimental 40W superconducting thruster using liquid nitrogen cooling

Measured Q =6.8x106

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The Next Step ?

EmDrive is a British Invention

R&D has been funded by UK Government and British investors

Within a few years:

Military satellites without EmDrive will not be Fit for Pupose

Commercial satellites without EmDrive will not be sold

Science missions without EmDrive will not be considered

Will UK military, commercial and scientific space interests exploit the technical lead we presently hold ?