ASTRO-G projectVSOP-2 – VLBI Space Observatory Programme - 2

10 times higher sensitivity.

10 times higher frequency observation

10 times higher resolution with ～ 40 arcseconds

Observing band 8, 22, 43 GHz

Dual polarization

Phase-referencing capability

The next generation space VLBI (SVLBI) mission following the VSOP mission.

9.26 m Antenna for

Radio Astronomy

Mass 1,300 kg (Nominal)

1 Gbps Data Downlink

~35,000 km

ASTRO-G project scientific objectives

Generate VLBI Array with Ground Radio Telescopes.

Magnetic fields of galaxies

Jets from the accretion disks around black holes

Radio galaxies

Quasars

Observe Astronomical Objects with the highest resolution.

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EAVN WS 2009 Mar 18

ASTRO-G Schedule

FY2006(H18)

2007(H19)

2008(H20)

2009(H21)

2010(H22)

2011(H23)

2012(H24)

2013(H25)

2014(H26)

2014(H27)

Review to be a pre-project

System Definition

Review (SDR)

Review forProject Start

Design Review

#1 （ PDR #1 ）

Concept Design

EDC Basic Design

Observing system Test

Integration TestInitial Orbit

Check

Science Operation

FlightOperation

Launch （ Planned ）

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Design Review

#2 （ PDR #2 ）

Design Review

#3 （ CDR ）

Earlier Development Components (EDC) (Main antenna, Ka Ant., Cryostat, Main Structure, Thruster Later Development Components (LDC): Observing system, GPS, SLR, and other BUS system

EDC Detailed Design

EDC Manufacture and Test

LDC Basic Design

LDC Detailed Design

LDC Manufacture and Test

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Current Status of ASTRO-G

• Satellite development– Current master schedule is based on the launch scheduled

to be 2013 January/February – We are now Basic Design Phase ... (Phase -B) .– Preliminary Design Review (PDR) for earlier development

subsystems (Antenna, KaANT, Structure, Thruster, Cryostat) have finished March 13, 2009. PDR of all system will be scheduled in March 2010.

– Mechanical and thermal mathematical model are made, and the checking the system based on the model is on going.

– Engineering Model of Horn to LNA was tested at ISAS till February.

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Current Status of ASTRO-G(Continued)

• Ground Facilities Some Unknown factors– Tracking station

• Usuda and Yebes (Spain)? now. One more?

– Ground Radio Telescopes• EAVN, EVN, Australia, VLBA(?) & US, S.Africa (?), …• Japanese activities, (JVN upgrade for VSOP-2). Science Support

– Correlators• KJJVC, and others (Software correlators ?)

• International Collaborations– VISC-2 meeting @ December, 2008. – Submit space VLBI proposal to US Decadal Survey

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RF Gain Requirement (43 GHz)Large deployable antenna system

Observing System Gain Requirements　 　 Requirements 　 BOL 　 EOL dBi

0Theoretical Value

　 Ideal Parabora 71.22 　 71.22 dBi

　 Loss by Antenna

SRUNT SRUNT Surface Loss -0.24 H -0.24 dB

　 　 SRUNT SRUNT Loss by Thermal Control Sheet -0.03 T -0.05 dB　 　 SRUNT SRUNT Reflection Loss -0.07 ※ -0.07 dB　 　 LDR LDR 0.4 mm rms loss. -2.25 A/H -2.25 dB　 　 LDR LDR Mesh Reflection Loss -0.61 T -0.61 dB

1Deformation Free Antenna Characteristic

Ideal Alignment Antenna Gain (Peak Gain) 68.02 　 68.00 dBi

　 Deformation in the orbit

LDR/Structure

Thermal Deformations for LDR 、 Main Structure, Sub-ref

-0.90 A -0.91 dB

　 　 （ after the pointing correction ）

　 　 LDR LDR deformation by radiation @ end of Life (EOL)

― 　 -0.89 ※dB

2 Thermal Deformation in the orbitGain with thermal deformation （ Peak Gain ） 67.12 　 66.21 dBi

　 Pointing Los

AOCS Error by Attitude Control System -0.29 A -0.29 dB

　 　 AOCS/LDR Antenna small vibration -0.01 A -0.01 dB　 　 System Pointing measurement error -0.13 A -0.13 dB

3 Observational Gain Observational Gain (including Pointing Loss)

66.69 　 65.77 dBi

A:Analysis ， H:Experience ， T:Experience/Test ， D: Desgin

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Radio Quiet Room in JAXACompact range system

(September 2008)

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1.5 m mesh antenna for RF test

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Thermal/VacuumTest for a moduleOf LDR (Aug. – Sept. 2008)

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22/43GHz(@ Sagamihara / JAXA)RF Test ＝＞ Vibration Test ＝＞ RF Test ＝＞ SHI へ（ 2008/11/1-2009/2/19 ）８ GHz(@ Osaka Pref. University)RF Test ＝＞ Vibration Test （ Sagamihara ）＝＞ RF

Test ＝＞ SHI 　（ 2008/11/1-2009 3/M ）

43 GHz (After Vibration Test)

OK!

OK!22 GHz Test Set (Sagamihara)

Frontend Development Status

Frequency [GHz]

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22 GHz (After Vibration Test)

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Summary

• Satellite development is on-going.– Engineering Model Test for Antenna, Frontend, etc.– PDR #1 is finished in March 13th, 2009.

• Currently it is in basic design phase (Phase-B)• International Collaboration is on-going.