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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]
10
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.