Technical review of the HALCA satellite Bus system: Power supply, Attitude Control Thruster Thermal

1
Technical review of the HALCA satelliteBus
systemPower supply, Attitude Control
(Thruster)Thermal ControlStructure,Telecommunic
ationsOnboard Data Processing Yasuhiro MURATA
(ISAS/JAXA)
2
HALCAVSOP History
AO1 1996
1
2
3
4
5
6
7
8
9
10
11
12
1997
GOT observatins
90 minutes Eclipse
LAUNCH
Antenna Deployment
First Ku Link
First Object (W49n OH)
Observation for First Finge
First Image
1998
R
R
90 minutes Eclipse
COSPAR
Telemetry Lost
22 GHz Fringe
Telemetry Lost
AO2
1999
R
R
R
URSI
Telemetry Lost
Telemetry Lost
Lost Attitude
AO3
RW-B Down
Biased Momentum (3-RW) Attitude Control
2000
VSOP Symposium
R
90 minutes eclispe
-ZSun attitude
AO5
?
AO4
R Recovery
-XSun attitude
HALCA in trouble
HALCA recovered but no observation
3
1
2
3
4
5
6
7
8
9
10
11
12
2001
AO6
2002
Stop to use DR
90min Eclipse
LAST OBSERVATION
2003
R
R
Spin Attitude
Spin Attitude
Spin Attitude
RWB,D, rotation test
RWD Spin Test
2004
RWB,D Rotation Test
Once a week Operation
2005
End of Operation
HALCA is in trouble
HALCA recovered but no observation
4
Number of VSOP observations
5
Final Operation 2005/11/30
6
Bad things
Power supply system Initial Setup Problem
Power-down _at_ long eclipse period. (Need
Confirmations) Observation must be start after
finishing charging. Produce Asymmetric UV
coverage. Attitude Control (Thruster) Initial
setup problem unexpected attitude in 1 st
pass. Used more fuels for thruster. (Perigee
1,000 ? 560 km) Changing of Sun Angle Constraint
(70 290 to 80 280) Lack of capacity of
Reaction Wheel Reaction Wheel failure _at_ 2000
Sun Angle Constraint (80-110) RW problem
terminated HALCA life. Shortage of the thruster
fuel. (Stop safe-hold mode)
7
Bad things
8
Bad things
Thermal Control System Failure of auto-control.
Sun Angle Constraint in 1998.
(80-100) Structure 22 GHz waveguide
Telecommunications No major problem /
Blockage by the main reflector On-board Data
Processing Degrade of onboard telemetry data
recorder (DR). (radiation) STT-B(Star Tracker),
IRU-F(Fiber Gyro), 1.6D/C, DR (TLM data
recorder) IRU-Z (Gyro-Z), RW-B, RW-D, CSAS-A
(Broken at EOL) Missing of telemetry (Hung up of
data handling unit.)
9
For VSOP-2/ASTRO-G
RW problem RW causes problem in some of JAXA
mission. Reliability of RW is all-JAXA problem.
Being studied deeply. Sun Angle Constraint 50
310 degree (But should not say better number
first.) Observation Constraint in
eclipse ASTRO-G can observe in short eclipse if
no fast switching.
10
Satellite Data Archive
Power Supply counted by current (A)
Time from the launch (days)
All telemetry data lt300 GB Thermal profile in
similar orbit Need to review telemetry date for
ASTRO-G