delfi-c - pa3wegdelfi-c3. 26 july 2009 annual amsat uk colloquium 2009 2 delfi-c3 – quick facts...

26 July 2009

Annual AMSAT UK colloquium 2009 1

Update and Flight ResultsWouter Weggelaar PA3WEG

Delfi-C3

26 July 2009


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

26 July 2009


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

26 July 2009


AWSSTFSC

TFSC: Thin Film Solar CellAWSS: Autonomous Wireless Sun Sensor

26 July 2009


PSLV-C9

26 July 2009


– 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

26 July 2009


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

26 July 2009


Ground segment

26 July 2009


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)

26 July 2009


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

26 July 2009


26 July 2009


Issues• TX dropouts due to databus issues• Resets due to databus issues• EPS issues in beginning of mission• All non critical• Transponder issues

26 July 2009


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

26 July 2009


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

26 July 2009


LNA +filters

Gain +filters

Telemetry and command RX paths not shown

26 July 2009


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

26 July 2009


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

0

2

4

6

8

10

12

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

0

2

4

6

8

10

12

14Last month

26 July 2009


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

26 July 2009


TFSC payload data

26 July 2009


TFSC curves harvested

In 3 months Science Mode more than53000 accurate I-V curves have been harvested

26 July 2009


WebSDR reception(1)

http://websdr.pa3weg.nl

26 July 2009


WebSDR reception(2)

http://websdr.pa3weg.nl

26 July 2009


[email protected]

http://www.delfic3.nl/

delfi-c - pa3wegdelfi-c3. 26 july 2009 annual amsat uk colloquium 2009 2 delfi-c3 – quick facts...

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