Young Bae - NASA's Institute for Advanced Concepts
Young Bae - NASA's Institute for Advanced Concepts
Young Bae - NASA's Institute for Advanced Concepts
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NIAC 8 th Annual Meeting: 2006<br />
Photon Tether Formation Flight (PTFF)<br />
<strong>Young</strong> K. <strong>Bae</strong>, Ph.D.<br />
<strong>Bae</strong> <strong>Institute</strong><br />
Tustin, Cali<strong>for</strong>nia, USA<br />
www.baeinstitute.com
NIAC 8 th Annual Meeting: 2006<br />
Participants<br />
• Joseph Carroll, Tether Applications Inc.<br />
-- General Tether Aspects and Hardware<br />
• Claude Phipps, Ph.D., Photonics Associates<br />
-- Nano-Newton Thruster Stand<br />
• Eugene Levin, Ph.D., STARS, Inc.<br />
-- Dynamics of Tethers and Formation Flying<br />
• Bob Scaringe, AVG Communications<br />
-- Business Development
NIAC 8 th Annual Meeting: 2006<br />
Examples of Revolutionary/Disruptive Technologies<br />
Key Enabling Factor:<br />
Orders of Magnitude Enhancement in Critical Parameters<br />
• Subatomic Dimension -- Particle Accelerators<br />
Critical Parameter: Particle Energy<br />
• Atomic Dimension – STM/AFM<br />
Critical Parameter: Scanning Ability/Noise Reduction<br />
• Molecular to Daily Life Dimension -- Lasers<br />
Critical Parameter: Coherence of Photons<br />
• Astronomical Dimension – Precision Formation Flying (?)<br />
Critical Parameter: Control Accuracy (?)
NIAC 8 th Annual Meeting: 2006<br />
Examples of Precision Formation Flying <strong>Concepts</strong><br />
TPF<br />
MAXIM<br />
SI Mission<br />
LISA<br />
SPECS
Control Accuracy<br />
NIAC 8 th Annual Meeting: 2006<br />
Selected Formation Flying Missions<br />
Baseline Distance<br />
GRACE<br />
>1 km<br />
SNAP 1<br />
Tsinghua<br />
1 m<br />
TechSat<br />
21<br />
DARWIN<br />
GEMINI<br />
1 mm<br />
XEUS<br />
ESA Proba-3<br />
Control Limitation with Conventional Thrusters?<br />
1 µ m<br />
SPECS<br />
MAXIM<br />
1 nm<br />
PTFF<br />
FTXR<br />
LISA<br />
1 m 10 m 100 m 1 km 10 km 100 km >1,000 km
NIAC 8 th Annual Meeting: 2006<br />
Nano-Meter Precision Spacecraft Formation Flying:<br />
-- is able to cover most of critical missions planned<br />
-- enables many other new missions<br />
• Thus, it is Potentially a Revolutionary/Disruptive<br />
Technology of the 21 st Century in Astronomical<br />
Dimension.<br />
• So far, its Enabling Technology has been illusive.<br />
• We believe that PTFF could be the Enabling Technology,<br />
if successfully demonstrated.<br />
• The Primary Goal of this NIAC Phase II is to demonstrate<br />
a sub-scale prototype PTFF engine.
NIAC 8 th Annual Meeting: 2006<br />
Photon Tether Formation Flight (PTFF)<br />
• Force Structure: Counter Balance of Two Forces:<br />
Contracting Force: Tether Tension<br />
Extending Force: Photon Thrust<br />
- Intracavity Arrangement<br />
- Thrust Multiplied by Tens of Thousand Times by Bouncing<br />
Photons between Spacecraft<br />
• Geometrical Structure: Crystalline Structure<br />
• Interspacecraft Distance Accuracy: better than nm<br />
• Maximum Operation Range: Tens of kms (Limited by<br />
Laser Mirror Size)<br />
• Can be Used <strong>for</strong> both Static and Dynamic Applications
NIAC 8 th Annual Meeting: 2006<br />
Major Advantages of PTFF<br />
• Ultra-High Baseline and Pointing Accuracy<br />
-- Baseline Accuracy: better than 1 Nano-Meter<br />
-- Pointing Accuracy: better than 0.1 micro-arcsec <strong>for</strong> 1 km baseline system<br />
– Enabling Wide Ranges of Imaging Missions<br />
• Propellantless<br />
-- System Mass Savings, Contamination Free, Long Mission Lifetime<br />
• Low Power Consumption<br />
• Low Construction Cost<br />
• Dual Usage of Photon Thruster Laser <strong>for</strong> Interferometric Ranging<br />
System<br />
-- Simplified System Architecture and Control, Low System Weight<br />
• Readily Downscalable to Nano- and Pico- Satellites Usage<br />
-- Ideal <strong>for</strong> Sophisticated Fractionated Spacecraft or Space Structures
NIAC 8 th Annual Meeting: 2006<br />
PTFF System Architecture<br />
Nano-Precision Formation Flying System Architecture<br />
Satellite I<br />
Satellite II<br />
Photon Thruster<br />
System<br />
Interferometric<br />
Ranging System<br />
Precision Laser<br />
Power Meter<br />
Lens<br />
Partial Mirror<br />
Photodetector<br />
Partial Mirror<br />
HR Mirror<br />
Intracavity Laser Beam<br />
Ultrahigh Precision CW Photon Thrust<br />
Laser Gain Media<br />
HR Mirror<br />
HR Mirror<br />
Pump<br />
Laser<br />
Beam<br />
Diode<br />
Pump<br />
Laser<br />
Partial Mirror<br />
HR Mirror<br />
Tether System<br />
Tether<br />
Reel<br />
Clamp<br />
Tether<br />
Tension<br />
Piezo-Translator<br />
Stepper Motor
NIAC 8 th Annual Meeting: 2006<br />
Photon Thruster System: TRL 3<br />
Satellite I<br />
Satellite II<br />
Lens<br />
Intracavity Laser Beam<br />
Laser Gain Media<br />
Pump<br />
Laser<br />
Beam<br />
Precision Laser<br />
Power Meter<br />
Ultrahigh Precision CW Photon Thrust<br />
HR Mirror<br />
HR Mirror<br />
Diode<br />
Pump<br />
Laser<br />
• Laser System<br />
-- Diode Pumped Intracavity Laser<br />
-- Lifetime of Diodes<br />
1 Year <strong>for</strong> Continuous Operation<br />
• Pump Diode Carousel Design – Tens of Years
NIAC 8 th Annual Meeting: 2006<br />
10000<br />
Intracavity Photon Thrust as a Function of the Mirror Reflectance (R)<br />
10 W System<br />
1000<br />
Photon Thrust (µN)<br />
100<br />
10<br />
1<br />
Predicted Capability of the Proposed System<br />
Off-the-Shelf<br />
Super Mirror<br />
0.1<br />
10 100 1000 10000 100000<br />
1<br />
1 - R
NIAC 8 th Annual Meeting: 2006<br />
Specific thrusts as functions of I sp of various conventional and photon thrusters.<br />
Intracavity Multiplication Factors<br />
10 -1<br />
10 0 X 1,000<br />
X 20,000<br />
X 10,000<br />
Specific Thrust (mN/W)<br />
10 -2<br />
10 -3<br />
10 -4<br />
10 -5<br />
Electric Thrusters<br />
Photon Thrusters<br />
X 100<br />
10 -6<br />
10 -7<br />
10 2 10 3 10 4 10 5 10 6 10 7 10 8<br />
I sp (sec)
NIAC 8 th Annual Meeting: 2006<br />
Photon Thruster System: Mirror Diameter vs. Operation Distance<br />
Mirror Diamter (cm)<br />
10<br />
1<br />
0.01 0.1 1 10 100<br />
Intersatellite Distance (km)
NIAC 8 th Annual Meeting: 2006<br />
Satellite I<br />
Interferometric Ranging System: TRL 5<br />
Satellite II<br />
Precision Laser<br />
Power Meter<br />
Lens<br />
Partial Mirror<br />
Intracavity Laser Beam<br />
Laser Gain Media<br />
Pump<br />
Laser<br />
Beam<br />
Partial Mirror<br />
HR Mirror<br />
Ultrahigh Precision CW Photon Thrust<br />
HR Mirror<br />
HR Mirror<br />
Diode<br />
Pump<br />
Laser<br />
Photodetector<br />
Partial Mirror<br />
HR Mirror<br />
• Dual Usage of Photon Thruster Laser <strong>for</strong> Interferometric<br />
Ranging System Source Laser<br />
-- System Architecture Simplification<br />
-- System Mass Reduction
NIAC 8 th Annual Meeting: 2006<br />
Heterodyne Interferometric Ranging System Integrated with Photon Thruster System<br />
Satellite I<br />
Satellite II<br />
Lens<br />
Partial Mirror<br />
Intracavity Laser Beam<br />
Laser Gain Media<br />
Pump<br />
Laser<br />
Beam<br />
Precision Laser<br />
Power Meter<br />
HR Mirror<br />
Ultrahigh Precision CW Photon Thrust<br />
HR Mirror<br />
Diode<br />
Pump<br />
Laser<br />
Beam Splitter<br />
AOM<br />
AOM<br />
Mirror<br />
Retroreflector<br />
Measurement<br />
Detector<br />
ODL<br />
Reference<br />
Detector
NIAC 8 th Annual Meeting: 2006<br />
Satellite I<br />
Tether System: TRL 5<br />
Electromechnical Damper<br />
Satellite II<br />
Tether<br />
Tether<br />
Reel<br />
Clamp<br />
Piezo-Translator<br />
Inchworm<br />
• Coarse Control: Reel System-- mm Accuracy<br />
• Fine Control: Inchworm or Stepper Motor-- µm Accuracy<br />
• Ultrafine Control: Piezo-Translator (off-the-shelf) -- 0.1 nm<br />
Accuracy
NIAC 8 th Annual Meeting: 2006<br />
Method of Tether Vibration Suppression<br />
• Major Tether Vibrations will Result from Reorientation of the Whole<br />
Formation Structure, and other Sudden Environmental Perturbations,<br />
such as Meteoroid Impacts.<br />
• Longitudinal Tether Wave Damping<br />
Tether Material Friction/ Modulation of Photon Thruster Power<br />
• Transverse Tether Wave Damping<br />
Electromechanical Damper with Impedance Matching<br />
Damping Applied<br />
Electromechanical Damping<br />
Simulation by Lorenzini et al.<br />
For 1 km Baseline System
NIAC 8 th Annual Meeting: 2006<br />
Example I: 10 km 1-D PTFF at L2
NIAC 8 th Annual Meeting: 2006<br />
Example II: 1 km PTFF Telescope at L2
NIAC 8 th Annual Meeting: 2006<br />
1 km PTFF Telescope:<br />
Enables New World Imager Freeway Mission<br />
By Prof. W. Cash – 2005 NIAC Fellow Meeting<br />
-- Searching <strong>for</strong> <strong>Advanced</strong> Civilization in Exo-Planets<br />
• 300 m resolution at 10 parsecs = 0.02 nano-arcseconds<br />
• 500,000 km based line distance between Collectors<br />
• Huge collecting area – one square kilometer
NIAC 8 th Annual Meeting: 2006<br />
More <strong>Advanced</strong> PTFF Telescope<br />
Image Processing<br />
With Real-Time<br />
Holographic<br />
Aberration<br />
Correction (NIAC)<br />
Stretched Membrane<br />
Mirror (NIAC)<br />
James Webb<br />
Space Telescope
NIAC 8 th Annual Meeting: 2006<br />
Technology Readiness Assessment Summary<br />
• Photon Thrusters: TRL 3<br />
• Interferometric Ranging System: TRL 5<br />
• Tether System: TRL 5<br />
• System Integration and Control: TRL 2<br />
• R&D 3 : II - III (moderate -high) (Degree of Difficulty)<br />
-- Requires to optimize photon thrust design based<br />
on the current laboratory system and system<br />
integration, and to develop control system.
NIAC 8 th Annual Meeting: 2006<br />
Phase II Work Started Since Sept. 1 st 2006<br />
• Proof-of-Concept Demonstration of Photon Thruster<br />
• Construction of a Thrust Stand with nN Accuracy<br />
• Overall System Stability and Control<br />
• Tether Vibration Dynamics<br />
• Environment Perturbation<br />
• 3-D Simulation<br />
• Design of Prototype Interferometric Ranging System<br />
• Design of Prototype Tether System<br />
• Detailed Study of Specific Applications<br />
• In-Depth Revisits of Existing <strong>Concepts</strong> -- SPECS and MAXIM<br />
• Ultralarge Membrane Space Telescopes<br />
• Ultralarge Sparse Aperture Space Telescopes<br />
• Others
NIAC 8 th Annual Meeting: 2006<br />
Prototype Sub-scale PTFF Engine Demonstration<br />
Counter<br />
Weight<br />
Interference Pattern<br />
Torsion<br />
Fiber<br />
Corner Cube<br />
Optical Fiber<br />
Low Power Laser<br />
Photo Detector<br />
<strong>for</strong> Fringe Monitoring<br />
Computer<br />
Windows<br />
Concave HR Mirror<br />
Laser Media<br />
Intracavity Laser Beam<br />
HR Mirror<br />
Pump Laser Diode<br />
Feedback<br />
Electronics<br />
Laser Power Meter<br />
Tether<br />
Vacuum Chamber<br />
Piezo-Translator
NIAC 8 th Annual Meeting: 2006<br />
Conclusions I<br />
• If successful, PTFF technology will be<br />
revolutionary/disruptive technology of 21 st Century<br />
in Astronomical Dimension.<br />
• If successful, PTFF technology will open new<br />
innovative (revolutionary) ways to implementing<br />
new and existing mission concepts at very<br />
af<strong>for</strong>dable costs. -- Many applications can be<br />
implemented at fractional costs of HST.<br />
• Preliminary Studies concluded that PTFF system<br />
can be implemented with off-the-shelf technologies<br />
– This will be tried to be proved during this study.
NIAC 8 th Annual Meeting: 2006<br />
Conclusions II<br />
• Mission Specific Applications<br />
• PTFF Simplifies the Architecture and Reduces the Weight<br />
in<br />
Space Interferometery Missions -- TPF, DARWIN,<br />
MAXIM,<br />
SPECS, FTXR etc.<br />
• Ultra-large PTFF Space Telescopes<br />
-- For New World Imager (300 m Resolution – Freeway<br />
Mission with km Mirror)<br />
-- Earth imaging/Monitoring/Surveillance (10 cm<br />
Resolution<br />
Monitoring at GEO with 200 m Mirror)
NIAC 8 th Annual Meeting: 2006<br />
The Support by NIAC and NASA <strong>for</strong> this project is greatly appreciated.<br />
“I believe in intuitions and inspirations.<br />
I sometimes feel that I am right.<br />
I do not know that I am.”<br />
by Albert Einstein
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