1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan)

DECIGO PathfinderDECIGO Pathfinder

Seiji Kawamura, Takashi Nakamura, Kimio Tsubono, Takahiro Tanaka, Ikkoh Funaki, Naoki Seto, Kenji Numata, Shuichi Sato, Seiji Kawamura, Takashi Nakamura, Kimio Tsubono, Takahiro Tanaka, Ikkoh Funaki, Naoki Seto, Kenji Numata, Shuichi Sato, Nobuyuki Kanda, Takeshi Takashima, Kunihito Ioka, Kazuhiro Agatsuma, Tomotada Akutsu, Tomomi Akutsu, Koh-suke Aoyanagi, Nobuyuki Kanda, Takeshi Takashima, Kunihito Ioka, Kazuhiro Agatsuma, Tomotada Akutsu, Tomomi Akutsu, Koh-suke Aoyanagi, Koji Arai, Yuta Arase, Akito Araya, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Motohiro Enoki, Yoshiharu Koji Arai, Yuta Arase, Akito Araya, Hideki Asada, Yoichi Aso, Takeshi Chiba, Toshikazu Ebisuzaki, Motohiro Enoki, Yoshiharu Eriguchi, Masa-Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Katsuhiko Ganzu, Tomohiro Harada, Eriguchi, Masa-Katsu Fujimoto, Ryuichi Fujita, Mitsuhiro Fukushima, Toshifumi Futamase, Katsuhiko Ganzu, Tomohiro Harada, Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng-Lei Tatsuaki Hashimoto, Kazuhiro Hayama, Wataru Hikida, Yoshiaki Himemoto, Hisashi Hirabayashi, Takashi Hiramatsu, Feng-Lei Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Hong, Hideyuki Horisawa, Mizuhiko Hosokawa, Kiyotomo Ichiki, Takeshi Ikegami, Kaiki T. Inoue, Koji Ishidoshiro, Hideki Ishihara, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Shogo Kamagasako, Nobuki Kawashima, Fumiko Kawazoe, Takehiko Ishikawa, Hideharu Ishizaki, Hiroyuki Ito, Yousuke Itoh, Shogo Kamagasako, Nobuki Kawashima, Fumiko Kawazoe, Hiroyuki Kirihara, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Hiroyuki Kirihara, Naoko Kishimoto, Kenta Kiuchi, Shiho Kobayashi, Kazunori Kohri, Hiroyuki Koizumi, Yasufumi Kojima, Keiko Kokeyama, WataruKokeyama, Wataru 　　 Kokuyama, Kei Kotake, Yoshihide Kozai, Hideaki Kudoh, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kokuyama, Kei Kotake, Yoshihide Kozai, Hideaki Kudoh, Hiroo Kunimori, Hitoshi Kuninaka, Kazuaki Kuroda, Kei-ichi Maeda, Hideo Matsuhara, Yasushi Mino, Osamu Miyakawa, Shinji Miyoki, Mutsuko Y. Morimoto, Tomoko Morioka , Kei-ichi Maeda, Hideo Matsuhara, Yasushi Mino, Osamu Miyakawa, Shinji Miyoki, Mutsuko Y. Morimoto, Tomoko Morioka , Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano, Isao Naito, Noriyasu Nakagawa, Toshiyuki Morisawa, Shigenori Moriwaki, Shinji Mukohyama, Mitsuru Musha, Shigeo Nagano, Isao Naito, Noriyasu Nakagawa, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Erina Nishida, Kazutaka Nishiyama, Kouji Nakamura, Hiroyuki Nakano, Kenichi Nakao, Shinichi Nakasuka, Yoshinori Nakayama, Erina Nishida, Kazutaka Nishiyama, Atsushi Nishizawa, Yoshito Niwa, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Akira Okutomi, Kouji Onozato, Kenichi Atsushi Nishizawa, Yoshito Niwa, Masatake Ohashi, Naoko Ohishi, Masashi Ohkawa, Akira Okutomi, Kouji Onozato, Kenichi Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shin-ichiro Sakai, Shihori Sakata, Misao Sasaki, Takashi Sato, Oohara, Norichika Sago, Motoyuki Saijo, Masaaki Sakagami, Shin-ichiro Sakai, Shihori Sakata, Misao Sasaki, Takashi Sato, Masaru Shibata, Hisaaki Shinkai, Kentaro Somiya, Hajime Sotani, Naoshi Sugiyama, Yudai Suwa, Hideyuki Tagoshi, Kakeru Masaru Shibata, Hisaaki Shinkai, Kentaro Somiya, Hajime Sotani, Naoshi Sugiyama, Yudai Suwa, Hideyuki Tagoshi, Kakeru Takahashi, Keitaro Takahashi, Tadayuki Takahashi, Hirotaka Takahashi, Ryuichi Takahashi, Ryutaro Takahashi, Takamori Takahashi, Keitaro Takahashi, Tadayuki Takahashi, Hirotaka Takahashi, Ryuichi Takahashi, Ryutaro Takahashi, Takamori Akiteru, Tadashi Takano, Keisuke Taniguchi, Atsushi Taruya, Hiroyuki Tashiro, Mitsuru Tokuda, Masao Tokunari, Morio Akiteru, Tadashi Takano, Keisuke Taniguchi, Atsushi Taruya, Hiroyuki Tashiro, Mitsuru Tokuda, Masao Tokunari, Morio Toyoshima, Shinji Tsujikawa, Yoshiki Tsunesada, Ken-ichi Ueda, Masayoshi Utashima, Hiroshi Yamakawa, Kazuhiro Yamamoto, Toyoshima, Shinji Tsujikawa, Yoshiki Tsunesada, Ken-ichi Ueda, Masayoshi Utashima, Hiroshi Yamakawa, Kazuhiro Yamamoto, Toshitaka Yamazaki, Jun'ichi Yokoyama, Chul-Moon Yoo, Shijun Yoshida, Taizoh YoshinoToshitaka Yamazaki, Jun'ichi Yokoyama, Chul-Moon Yoo, Shijun Yoshida, Taizoh Yoshino

Masaki AndoMasaki AndoDepartment of Physics, the University of TokyoDepartment of Physics, the University of Tokyo

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 2

OverviewOverview

　　　　　　　　　　　　　　　　　　 Mission payloadMission payload

Noise estimationNoise estimation

Current statusCurrent status

SummarySummary　

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 3

OverviewOverview　

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 4

DECIGO RoadmapDECIGO Roadmap

Figure: S.Kawamura

2007

08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Missio

nO

bjective

Test of key technologiesGW observation at low frequencies

Detection of GW w/ minimum spec.Test FP cavity between S/C

Full GW astronomy

Desig

n

1 S/C1 Fabry-Perot arm

3 S/C1 interferometer

3 S/C,3 interferometer3 or 4 units

DICIGO Pathfinder (DPF)

Pre-DECIGO DECIGO

R&DFabrication

R&DFabrication

R&DFabrication

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 5

DECIGO PathfinderDECIGO Pathfinder

DECIGO Pathfinder (DPF)　　 One small satellite (Weight: ~350kg, Orbit: around the Earth) 30cm Fabry-Perot cavity formed by free masses Stabilized laser source Drag-free control system

Local Sensor

Actuator

Thruster

Scientific observation　　　 Low-frequency (0.1-1Hz) GWs　　 Intermediate-mass BHs at the Galactic center 　 Gravity distribution of Earth

Test and demonstration for DECIGO　　　 Laser stabilization system Control of Fabry-Perot interferometer　　　 Drag-free control system

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 6

DPF SatelliteDPF Satellite

Size : 950mm cubeWeight : 200kgSAP : 940W Battery: 50AHDownlink : 2MpbsDR: 1GByte3N Thrusters x 4

Stabilized Laser

Interferometer Module

Thruster Control Unit

Solar Paddle

Interfererometer Control Unit

Housing Control Unit

Mission Thrusters

Central Processing Unit

Bus Thrusters

Satellite Bus (‘Standard bus’ system)

DPF PayloadSize : 950mm cubeWeight : 150kgPower : 120WData Rate: 800kbpsMission thruster x12

Power SupplySpW Comm.

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 7

DPF Mission OutlineDPF Mission Outline

Orbit: Low-Earth (Altitude 500km), Sun-synchronous orbit (dusk-dawn)

Launcher: Single launch by M-V follow-on (solid rocket booster under development) PBS (Post-Boost stage) for fine orbit insertion

Mission Lifetime: 1 year (nominal)

500km

DP

F

Attitude Control: Gravity-gradient stab. Drag-free control with mission thrusters

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 8

Mission payloadMission payload　

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 9

DPF Payload DPF Payload

Fabry-Perot interferometer 　 Finesse : 100 　 Length : 30cm 　 Test mass : 1kg Signal extraction by PDH

Laser source Yb:YAG laser (1030nm) Power : 25mW Freq. stab. by Iodine cell

Drag-free control Local sensor signal 　　 Feedback to mission thrusters

Weight : ~150 kgSize : ~95 cm cube

Upper half of the satellite

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 10

Stabilized laser Stabilized laser

Laser source Yb:YAG laser (1030nm) Power : 25mW Freq. stab. by Iodine absorption line 0.5 Hz/Hz1/2 (at 0.1Hz)

Comparable stability with that by a reference cavity at 0.1Hz

Advantage of I2 stabilization

Less affected by environment Easier ground-base tests Moderate vibration isolation No vacuum system

Disadvantages Less experience

Narrow absorption line at 515nm

Musha-san and Nagano-san’s talks tomorrow

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 11

Main interferometer Main interferometer

Test-mass module Keeps a test inside Local sensor/actuator Launch-lock system Interferometer sensors for fine measurement

Sato-san’s talk tomorrow

Fabry-Perot interferometer 　 Finesse : 100 　 Length : 30cm 　 Test mass : ~1kg Signal extraction by PDH

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 12

Drag-free and attitude controlDrag-free and attitude control

Drag-free control for demonstration of control system suppression of external disturbances (solar radiation, air drag, …)

Passive + Active stabilization Passive stabilization by gravity-gradient Mast (~30kg) attached for MOI adj. Active drag-free with 12 mission thrusters

Satellite Bus Attitude control at initial phase and fail safe 3N thruster x4, Magnetic torquer x3 Solar sensor, Fiber gyroscope

Requirement: 10-9 m/Hz1/2 (0.1Hz) for satellite disp.

Mast

Moriwaki-san’s talk tomorrow

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 13

DPF SensitivityDPF Sensitivity

Satellite mass : 350kg, Area: 2m2

Altitude: 500kmThruster noise: 0.1μN/Hz1/2

Laser source : 1030nm, 25mW IFO length : 30cmFinesse : 100, Mirror mass : 1kgQ-factor : 105, Substrate: Fused SilicaTemperature : 293K (Preliminary

parameters)

10–2 10–1 100 101 10210–18

10–17

10–16

10–15

10–14

10–13

10–12

10–11

10–18

10–17

10–16

10–15

10–14

10–13

10–12

No

ise

leve

l

[1/H

z1/2

]

Frequency [Hz]

Shot noise

Mirror thermal

Laser Radiation

Laser: 1030nm, 25mWFinesse: 100Mirror mass: 1kgQ–value of a mirror: 106

Cavity length: 30cm

pressure noise

Thruster noise

PM acceleration Noise

Geog

ravity Laser Frequencynoise

Dis

pla

cem

ent

No

ise

[m

/Hz1

/2]

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 14

DPF TargetsDPF Targets

Quasi-normal mode oscillation

Binary inspiral of BHs

103 104 105 10610–1

100

101

102

Ob

serv

able

Ran

ge

Mass [Msolar]

[kp

c, S

NR

=5

]

Galactic Center

BH QNM

BH Inspiral

Detectable with SNR~5

h ~ 10-13 , f ~ 0.3 Hz Distance 10 kpc, m = 105

Msun

h ~ 10-15 , f ~ 4 Hz Distance 10kpc, m = 103

Msun

Science target: Intermediate-mass BHs at GC

KAGAYA

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 15

Noise estimationNoise estimation　

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 16

Comparison with LPFComparison with LPF

LPF (LISA Pathfinder)DPF (DECIGO Pathfinder)

Stabilized Laser

Interferometer Module

Thruster Control Unit

Solar Paddle

Interfererometer Control Unit

Housing Control Unit

Mission Thrusters

Central Processing Unit

Bus Thrusters

Purpose Launch

WeightOrbit

Test MassLaser sourceInterferometerSensitivity

Demonstration for LISA

2010Dedicated launcher (Vega)

1,900 kg Halo orbit around L1

Drag-free attitude controlAu-Pt alloy x2

Nd:YAG (1064nm)Mach-Zehnder

3x10-14 m/s2/Hz1/2 (1mHz)

Demonstration for DECIGO GW observation

~2012Dedicated launcher (M-V follow-on)

350 kg SSO altitude 500km

Drag-free attitude controlTBD x2

Yb:YAG (1030nm)Fabry-Perot

1x10-15 m/s2/Hz1/2 (0.1Hz)

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 17

Gravity-gradient noise Gravity-gradient noise

Global gravity field model Public data obtained by GRACE　 Up to 2190 th-order coefficients in spherical harmonicsSatellite velocity of 5km/sec

Sufficiently small at 0.1Hz band10-7 m/s2 acceleration at low freq.

10–2 10–1 100 101 10210–18

10–17

10–16

10–15

10–14

10–13

10–12

10–11

10–10

10–9

Acc

eler

atio

n N

ois

e [

m/s

2 /Hz1

/2]

Frequency [Hz]

Shot noise

Mirror th

ermal

Laser Radiationpressure noise

Radiation Pressure

of the Sun

PM acceleration Noise

Earth's Tidal force

Satellite moves in the gravity field of Earth

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 18

Geomagnetic noise Geomagnetic noise

Public data at Esashi observatory 1 sample/min data Extrapolate for higher frequency

Two effect by geomagnetic field

10–3 10–2 10–1 10010–6

10–4

10–2

100

102

104

Mag

net

ic n

ois

e [

nT/

Hz1

/2]

Frequency [Hz]

(N–S Direction)

(Vertical Direction)

Geomagnetic FieldFluctuation

S/C motion

S/C Motion

Geomagnetic field model IGRF-10 model (10th generation of International

Geomagnetic Reference Field) Altitude 500km Satellite velocity of 5km/sec

Satellite self-field

Effect of geomagnetic field: smaller than satellite self-field ~10-7 T noise level ~ 1.5 x 10-16 m/s2/Hz1/2

10–2 10–1 100 101 10210–18

10–17

10–16

10–15

10–14

10–13

10–12

10–11

Ac

ce

lera

tio

n N

ois

e [

m/s

2 /Hz1/

2]

Frequency [Hz]

Shot noise

Mirror th

ermal

Laser Radiationpressure noise

Radiation Pressure

of the Sun

PM acceleration Noise

Earth's Tidal force

DPF total

Magnetic-field noise

Fluctuation in geomagnetic field

Satellite motion in magnetic field

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 19

Noise sourcesNoise sources

Residual Gas

Thermal radiation

Magnetic field

Laser freq. noise

Force Acceleration Acceleration noise Displacement noise

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 20

Current StatusCurrent Status　

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JAXA’s small satellite seriesJAXA’s small satellite series

Plan to launch 3 small satellites by the year 2015 using next-generation solid rocket booster Reduce time and cost by means of ‘Standard bus system’

Bus weight : ~ 200kg, Bus power : ~ 900W 　 Downlink ~ 2Mbps, Data storage ~ 1GByte 3-axes attitude control SpaceWire-based data processing system

1st mission (2011) : decided to be TOPS (Planetary science)

2nd mission will be selected by 2009 March

5 Candidate missions ERG: Plasma and particle detector for geo-space investigation DPF: GW observation DIOS: X-ray telescope for dark baryon investigation Satellite for Magnet-plasma sail technology demonstration, …

Image CG of TOPS (design has been changed now)

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 22

DPF Current statusDPF Current status

Laser frequency stabilizationMirror and its housing Micro thrusterDrag-free control simulationDetailed design and noise investigation

Submitting Phase-A proposal R&D for core technologies

Proposing to launch in 2012 as 2nd small satellite of JAXA

2005  Jan. 　 Submit a proposal of small GW detector mission2006 Nov. 　 Submit a proposal of GW-detector satellite as DECIGO pathfinder (DPF)2007 Aug. Selected as a Pre-Phase-A mission R&D costs funded

Brief History

Precursor: Small GW sensor (SWIM) to be launched in FY2008

SWIM fixed to SDS-1 satellite (July 11, 2008)

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 23

SWIMSWIM

Sensor module to demonstrate SpW communicationObservation of gravitational waves (10-7 /Hz1/2)Monitor the satellite environment as accelerometers

SWIM : Tiny gravitational-wave detector

Test mass

Photo sensor

Coil

TAM: Torsion Antenna Module with free-falling test mass (Size : 80mm cube, Weight : ~500g)

Reflective-type optical displacement sensorSeparation to mass ~1mmSensitivity ~ 10-9 m/Hz1/2

6 PSs to monitor mass motion

~47g Aluminum, Surface polishedSmall magnets for position control

Used for test-mass position controlMax current ~100mA

2 TAMs in the

frame

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 24

SWIMSWIM

Small module for demonstration of SpaceWire-based data processing system

SWIM (Space wire demonstration module)Total system Size : 220x200x180 Weight ~ 5.6 kg Power ~ 14 W

One of main missions of SDS-1

CPU: HR5000 (64bit, 33MHz) System Memory: 2MB Flash Memory 4MB Burst SRAM 4MB Asynch. SRAM Data Recorder: 1GB SDRAM 1GB Flash Memory SpW: 3ch

Comprised of SpaceCube2 and SWIM

SpaceCube2: Space-qualified Computer

SWIM : User Module Processor test board GW+Acc. sensor FPGA board DAC 16bit x 8 ch ADC 16bit x 4 ch 32 ch by MPX Torsion Antenna x2 ~47g test massSize: 71 x 221 x 171

Weight: 1.9 kg Power: 7W

Power ±15V, +5V SpW x2 for CMD/TLM

Data Rate : 380kbps Size: 124 x 224 x 174 Weight: 3.5 kg Power: ~7W

Power +28V RS422 for CMD/TLMGPS signal

SDS-1 Bus System

Current status: Fixed to SDS-1 CMD/TLM checked

Photo by JAXAPhoto by JAXA

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 25

SDS-1SDS-1

Small satellite for demonstration of space technologies

SDS-1 (Small Demonstration Satellite)

Size : 70x70x60cm,Weight : 100kgPower : >100W, Downlink : ~5kbps Orbit : SSO (~660km)Spin stabilization and 3-axis attitude controlMission Lifetime : ~Half year (nominal)

Launch: FY2008 by H-IIA (piggy-back)

http://www.iat.jaxa.jp/info/prm/2007/019/01.html

SDS-1 and GOSAT (Press Release, November 4, 2008) Photo from Nainich Newspapser Web

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 26

SummarySummary　

1st International LISA-DECIGO Workshop (November 12-13, 2008, JAXA/ISAS, Sagamihara, Japan) 27

SummarySummary

　　 One small satellite (Weight: ~350kg, Orbit: around the Earth) 30cm Fabry-Perot cavity formed by free masses Stabilized laser source Drag-free control system

Local Sensor

Actuator

Thruster

Gravitational-wave observationTest and demonstration for DECIGO

DECIGO Pathfinder: First precursor satellite for DECIGO

Selected and funded as one of the candidates of JAXA’s small satellite missions Hoping to be launched in 2012

Observation band : 0.1Hz-1HzTarget : IBHs at the Galactic center

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EndEnd