Post on 24-Jul-2020
26 July 2009
Annual AMSAT UK colloquium 2009 1
Update and Flight ResultsWouter Weggelaar PA3WEG
Delfi-C3
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Annual AMSAT UK colloquium 2009 2
Delfi-C3 – quick facts• 3U CubeSat• NO Battery• NO active attitude control• 1200Bd BPSK downlink• Linear transponder• Payloads:
– Thin Film Solar Cells– Autonomous Wireless Sun Sensor
• Start project November 2004• Launched 28th of April 2008• > 60 student team
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Annual AMSAT UK colloquium 2009 3
Frequencies• Primary telemetry downlink
145.870MHz, 1200Bd BPSK AX.25 approx. 100mW• Backup telemetry downlink
145.930MHz, 1200Bd BPSK AX.25 approx. 200mW• Transponder downlink:
145.880-145.920MHz linear (inverting)CW beacon 10mW at 145.870MHz (Hi Hi de Delfi-C3 Delfi-C3)
• Transponder uplink: 435.570-435.530MHz40kHz passband, 400mW PEP435.556MHz = 145.900MHz
• Difference in downlink power caused by coupling capacitor having the wrong value of 10pF instead of 10nF
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Annual AMSAT UK colloquium 2009 4
AWSSTFSC
TFSC: Thin Film Solar CellAWSS: Autonomous Wireless Sun Sensor
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Annual AMSAT UK colloquium 2009 5
PSLV-C9
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– Full Mission Success (!)– 454 days of operation as of today– Radio Amateur Transponder degraded after a
while, beyond normal useability– All other subsystems fully operational– Stability problems on I2C bus– Problems with data analysis, hard to make
conclusions on payload performance– No critical problems or significant degradation to
predict EOL
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Annual AMSAT UK colloquium 2009 7
Radio amateur network• Overwhelming response from the amateur
radio community• 328 amateurs (others on guest account)• >3000 downloads of RASCAL• Top submitters
– JA0CAW– ZL2BX– PA0DLO– OH8MBN– PE1ITR
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Annual AMSAT UK colloquium 2009 8
Ground segment
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Annual AMSAT UK colloquium 2009 9
2008-04-282008-05-15
2008-06-012008-06-18
2008-07-052008-07-22
2008-08-102008-08-27
2008-09-132008-09-30
2008-10-172008-11-03
2008-11-202008-12-07
2008-12-242009-01-10
2009-01-272009-02-13
0
2000
4000
6000
8000
10000
12000
14000
Packets per day
Total number of packets: 699777
(approx. 100.1 MB)
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Annual AMSAT UK colloquium 2009 10
Improvements on RASCAL• 1.1.0
– Increased bandwith of tracking loop– Minor bugfixes
• 1.1.1 (soon to be released)– Added AWSS presence indicators– Cleaned up the code– Reference diode information added
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Annual AMSAT UK colloquium 2009 11
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Annual AMSAT UK colloquium 2009 13
Issues• TX dropouts due to databus issues• Resets due to databus issues• EPS issues in beginning of mission• All non critical• Transponder issues
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Annual AMSAT UK colloquium 2009 14
Timeline28 April 2008, 03:53 UTC Launch
06:39:08 UTC First received by Rick Mann (US)
11:49:51 UTC First reception in Delft
30 April 2008, 10:50:42 UTC
15 May 2008 Designated DO-64
29 July 2008, 10:00 UTC Switch from Science Mode to Transponder
End of September 2008 First signs of transponder degradation
14 October 2008, 11:00 UTC Switch to Basic Mode to investigate
29 January 2009, 09:33:17 UTC Switch to Science Mode
Delfi-C3 CDHS set to Read-Only mode
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Annual AMSAT UK colloquium 2009 15
Transponder issues– Diagnostic test results:
• Local oscillator and uplink frequency OK for both RHCP and LHCP polarization
• Over 400 W uplink power required to get a marginal downlink• Not useful for radio amateurs• Transponder IF at full gain• Corresponding command receiver also not working
– Conclusion:• Somewhere in the chain between antennae and power splitter there
is a short or an open connection• Can be anything: Bad cable or solder joint, failed component, tin
whisker, etc.• No further actions possible from ground• Unfortunately no AO-16 alike loopback due to time constraints
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Annual AMSAT UK colloquium 2009 16
LNA +filters
Gain +filters
Telemetry and command RX paths not shown
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Annual AMSAT UK colloquium 2009 17
Performance of passive attitude control
Modelled performance of design: Rotation with passive magnetic (hysteresis) material within a few orbits to 0.2 - 2 o/s from a max. of 10 o/s after ejection from X-POD
Actual:In the order of weeks before attitude gets from 9o/s to about 1o/s
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Annual AMSAT UK colloquium 2009 18
Bus voltage
2008-04-28 13:57:252008-05-02 03:28:37
2008-05-03 23:21:162008-05-06 02:12:44
2008-05-08 21:36:262008-05-11 22:39:30
2008-05-15 22:11:212008-05-20 11:10:49
2008-05-23 21:29:412008-05-27 11:48:52
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14First month
2009-01-25 00:03:332009-01-26 14:42:23
2009-01-28 11:54:482009-01-30 17:16:44
2009-02-03 13:48:212009-02-09 18:47:27
2009-02-15 22:51:352009-02-23 12:01:18
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14Last month
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Annual AMSAT UK colloquium 2009 19
Antenna shadingreference diode ouput
0,0
10,0
20,0
30,0
40,0
50,0
60,0
70,0
0 50 100 150 200 250 300 350 400 450
time [s]
sola
r asp
ect
an
gle
[d
eg
]
SA+X SA-X
SA+Y SA-Y
t=0: 28-05-2008 22:05:14 hrs CET
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Annual AMSAT UK colloquium 2009 20
TFSC payload data
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Annual AMSAT UK colloquium 2009 21
TFSC curves harvested
In 3 months Science Mode more than53000 accurate I-V curves have been harvested
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Annual AMSAT UK colloquium 2009 22
WebSDR reception(1)
http://websdr.pa3weg.nl
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Annual AMSAT UK colloquium 2009 23
WebSDR reception(2)
http://websdr.pa3weg.nl
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Annual AMSAT UK colloquium 2009 24
www.delfic3.nlpa3weg@amsat.org