Solar Power Satellite- Toward Unexplored Frontier with Nobel Technologies -

@ Moonshut International SymposiumWG3 : Expanding frontiers through co-evolution of AI and robots

Naoki ShinoharaProfessor

Research Institute for Sustainable Humanosphere Kyoto University, Japan

shino@rish.kyoto-u.ac.jp1

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Solar Power Satellite (SPS)

1GW Solar Power Station2kmφ Solar Cells2kmφ Microwave Antenna< 10,000 ton weight 36,000km

Wireless Power Transfer(via Microwave) [WPT]

2 - 4kmφReceiving Antenna

Energy Availability Factor Ground PV

: < 15% (Night, Rain…)Space PV (SPS)

: >90% (No Night in 36,000km Orbit,No Rain by Microwave Propagation)

-> SPS is huge, stable, and CO2-less future power station

Significance of SPS

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Mile Stone toward Future Space Development(Huge Space Satellite (Structure))

Future Stable Solar Power Station without CO2(Huge Solar Power from Satellite)

[Key Technologies for SPS]• Economical Launch System (Reusable Rocket, OTV, etc.)

• Totally <10,000 tons Space Segment• Construction/Maintenance of Huge Space Segment (by Robots a d AI)

• > 2km Structure in space with Solar Cells and WPT (Wireless Power Transfer)• Power Management in Plasma

• > 1 Million kW (1GW) Power (> 10-100kV in Plasma)• Wireless Power Transfer Technology (by Microwave, Laser)

• 36,000km WPT with > 50% (Electricity -> WPT (>90%)-> Electricity)

Various SPS ModelsSolar Power Satellite

Non-Concentrator Concentrator

Bus Power Bus PowerDistributed Power Distributed Power Laser Direct Excitation

NASA Reference Model

SPS2000 (Experiment)

NEDO Grand Design

USEF Tether SSPSNASA Sun Tower

NASA ISC

NASDA 2001

JAXA M-SSPS

JAXA L-SSPS

IAA Study Model

Designed in Japan

SPS-alpha (US)

First SPS (Glaser, P.E.)

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CASSIOPeiA (UK)

MR-SPS (CAST, China) SPS-omega (China)

System Size is the same(1GW power, a few km size, < 10,000 tons satellite)-> Required Technology is similar.

Scale of Space Structure

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SPS

Space ColonyInternational Space Station

Modular Reflector

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How to Launch > 10,000 tons Space Segment2 Step Launch (Ground→LEO(400km), LEO→GEO(36,000km)

Final Assembly, ExpansionData Relay Satellite

Orbiter Transfer Vehicle(OTV)

Construction Platform

Supply Station

Module Construction

RectennaTracking, Control

“Mission Image of Japanese SPS”, NEDO SSPS Report, 1994

How to Construct/Maintain > 2km Space Structureby Robot for SPS Construction/Maintenance

7NASDA (JAXA) SSPS Report, 2001

Structure Friendly RobotRobot Friendly Structure

Robotin Space

Storage

Robot on Structure

Image of SPS Structure (Solar Cell, WPT)(Easy Construction)

Unit Structure (Micro : Rigid, Macro : Soft)Actively Fluctuated Structure

< 2 km

Test Bed of Automatic Construction of SPS Structure on Ground

8Construction of Large Structure

StorageExpansionSupport of Expansion of Structure

Move, Transportation on Soft Structure

Inflatable StructureConstruction

Connection of Soft Structure

Supply, Parts Transportation

JAXA, SSPS Robot WG 2004

[Future Works]• Move, Transportation on Soft and Light Structure• Construction of Soft Structure• Remote Control / Self-Reliance Operation

Significance of SPS

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Mile Stone toward Future Space Development(Huge Space Satellite (Structure))

Future Stable Solar Power Station without CO2(Huge Solar Power from Satellite)

[Key Technologies for SPS]• Economical Launch System (Reusable Rocket, OTV, etc.)

• Totally <10,000 tons Space Segment• Construction/Maintenance of Huge Space Segment (by Robots and AI)

• > 2km Structure with Solar Cells and WPT• Power Management in Plasma

• > 1 Million kW (1GW) Power (> 10-100kV in Plasma)• Wireless Power Transfer Technology (by Microwave, Laser)

• 36,000km WPT with > 50% (Electricity -> WPT (>90%)-> Electricity)

Spin Off/In Technology for/from Commercial WPT

Proposal of Spin-off / Landing Applications of SPSby JAXA (2017)

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• Laser Power Transfer to Flying Drone • Laser Power Transfer to Driving Rover on Moon

• Microwave Power Transfer to Stratospheric Platform (>MW)

• Radar Rain Gauge with Large Expanded Structure (> 30m)

WPT to Flying Drone with Phased Array with New GaN Solid State Devices in FY2018

[R&D Project toward SPS by METI (2009-14, 15-16, 17-18, 19- )]

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Rectennas

Beam Direction Control（Pilot Signal Receiver)

Transmitter

Payload on Drone(Pilot Signal Transmitter + Rectennas)

Signal Monitor

Pilot SignalTransmitter

• Microwave frequency : 5.8GHz• 1.6kW MW Power (Max)• REV (Rotating Electric-field Vector Method)+ Retrodirective Beam Direction Control• Height 10m, 30m• Checking Target Detecting

and Beam Steering• Received Electric Power 42W @ 30m

METI : Ministry of Economy, Trade and Industry

Beam WPT via Radio Wave in Japan[MPT to Flying Drone Demonstration (2019.5.24)]

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Frequency : 5.8GHzCW, Tx MW Power : 1.6kW, Distance : 30m, Rx DC Power : 42WDeveloped by Mistubishi Electric, IHI Aerospace, conducted by J-Spacesystems, funded by METIShinohara is a chair of steering committee

Microwave Power Supply System for Moving Robot(Project of ‘Center of Innovation’ supported by JST (2013- )

Microwave Beam Control for Moving Robot

Power Transmission

SystemReceiving Unit

Power Monitoring

Microwave Beam

by Kyoto Universitywith Panasonic co.in 2015

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Various Commercial WPT Products in the World

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Inductive WPT (Magnetic Field)

WPT via Radio Wave (Microwave, UHF)OWPT

De facto standard with > 500 companies, including Apple

World Regulation in IEC, ISO, ITU, etc.

WPT is suitable for autonomous and unconscious systemlike robot with AI.

Working Document Towards a Preliminary Draft New Report ITU-R SM.[WPT.WIDE-BEAM.IMPACTS] rev. (2019）

15In Japan, we start discussion for new WPT regulation in MIC and will decide it before the end of FY2019MIC : Ministry of Internal Affairs and Communications

System System 1 System 2 System 3

Spec.

Frequency920 MHz bands(915-930 MHz)

2.45 GHz bands(2.40-2.499 GHz)

5.7 GHz bands(5.470-5.770 GHz)

Output Power 1 W 15 W 32 W

Antenna gain 6 dBi 24 dBi 30 dBi

EIRP 4 W (36 dBm) 65 dBm 70 dBm

Modulation TBD TBD TBD

Place of use Indoor Indoor Indoor

System specifications of beam WPT at the first step commercialization (2020)

Application of wide-beam WPT technology for wireless charger of mobile devices (System2,3)

Application of wide-beam WPT technology for wireless powered sensor network (System1)

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Roadmap to SPS by METI (2017)

On Ground Phase In Space PhaseAlreadyFinished

On GoingUnknown…No Guarantee…

Spin Off for Commercial Applications / Space Applications

Spin Off/In for/from Commercial Applications/ Space Applications

Power

StructureLaunch

Significance of SPS

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Future Stable Solar Power Station without CO2(Huge Solar Power from Satellite)

Population Explosion

Energy Problem Global Warming

Space DevelopmentExpanding Frontiers

From Closed-Earth SystemTo Open-Space SystemHow to Solve

The problems

Mile Stone toward Future Space Development(Huge Space Satellite (Structure))

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The Limits to Growth by Rome ClubWORLD-2 Model Simulation

•Meadows, D. H., D. L. Meadows, J. Randers, and W. W. Behrens III ; "The limits to growth - A report for THE CLUB OF ROME'S project on the predicament of mankind", Universe Books, New York, 1972

Computer SimulationWith Parameters in 1970

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The Limits to Growth by Rome ClubWORLD-2 Model Simulation

•Meadows, D. H., D. L. Meadows, J. Randers, and W. W. Behrens III ; "The limits to growth - A report for THE CLUB OF ROME'S project on the predicament of mankind", Universe Books, New York, 1972

Computer SimulationWith Parameters in 1970

with SPS

•Yamagiwa, Y. and M. Nagatomo ; "An Evaluation Model of Solar Power Satellites Using World Dynamics Simulation", Space Power, vol.11, no.2, pp.121-131, 1992

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SDGs with Harmonization with Human and Nature(on Closed-Earth System of Sustainable Humanosphere)

+ SGDs with Space Development(Open-Space System)

+Key Mile Stone

: SPS

SDGs : Sustainable Development Goals

Not Enough!

The Moon Speech - John F. Kennedy at Rice University - September 12, 1962

“We choose to go to the moon. Wechoose to go to the moon in thisdecade and do the other things, notbecause they are easy, but becausethey are hard, because that goal willserve to organize and measure thebest of our energies and skills, becausethat challenge is one that we arewilling to accept, one we are unwillingto postpone, and one which we intendto win, and the others, too.”

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December 18, 2019, in Japan “We choose to build Solar PowerSatellite. We choose to start to buildSolar Power Satellite in this decade(and to build SPS in 2050) and dothe other things, not because theyare easy, but because they are hard,because that goal will serve toorganize and measure the best ofour energies and skills, because thatchallenge is one that we are willingto accept, one we are unwilling topostpone, and one which we intendto win, and the others, too.”

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