Delfi-C 3 Update and Flight Results Wouter Weggelaar PA3WEG 1
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 2
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: 435.570-435.530MHz 40kHz passband, 400mW PEP 435.556MHz = 145.900MHz Difference in downlink power caused by coupling capacitor having the wrong value of 10pF instead of 10nF 3
TFSC AWSS TFSC: Thin Film Solar Cell AWSS: Autonomous Wireless Sun Sensor 4
PSLV-C9 5
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 6
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 7
Ground segment 8
Total number of packets: 699777 (approx. 100.1 MB) Packets per day 14000 12000 10000 8000 6000 4000 2000 0 2008-05-15 2008-06-18 2008-07-22 2008-08-27 2008-09-30 2008-11-03 2008-12-07 2009-01-10 2009-02-13 2008-04-28 2008-06-01 2008-07-05 2008-08-10 2008-09-13 2008-10-17 2008-11-20 2008-12-24 2009-01-27 9
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 10
11
12
Issues TX dropouts due to databus issues Resets due to databus issues EPS issues in beginning of mission All non critical Transponder issues 13
Timeline 28 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 29 July 2008, 10:00 UTC End of September 2008 14 October 2008, 11:00 UTC 29 January 2009, 09:33:17 UTC Delfi-C3 CDHS set to Read-Only mode Designated DO-64 Switch from Science Mode to Transponder First signs of transponder degradation Switch to Basic Mode to investigate Switch to Science Mode 14
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 15
LNA + filters Gain + filters Telemetry and command RX paths not shown 16
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 17
Bus voltage First month 14 12 10 8 6 4 2 0 2008-05-02 03:28:37 2008-05-06 02:12:44 2008-05-11 22:39:30 2008-05-20 11:10:49 2008-05-27 11:48:52 2008-04-28 13:57:25 2008-05-03 23:21:16 2008-05-08 21:36:26 2008-05-15 22:11:21 2008-05-23 21:29:41 Last month 14 12 10 8 6 4 2 0 2009-01-26 14:42:23 2009-01-30 17:16:44 2009-02-09 18:47:27 2009-02-23 12:01:18 2009-01-25 00:03:33 2009-01-28 11:54:48 2009-02-03 13:48:21 2009-02-15 22:51:35 18
Antenna shading reference diode ouput 70,0 t=0: 28-05-2008 22: 05: 14 hrs CET SA+X SA-X SA+Y SA-Y 60,0 solar aspect angle [deg] 50,0 40,0 30,0 20,0 10,0 0,0 0 50 100 150 200 250 300 350 400 450 time [s] 19
TFSC payload data 20
TFSC curves harvested In 3 months Science Mode more than 53000 accurate I-V curves have been harvested 21
WebSDR reception(1) http://websdr.pa3weg.nl 22
WebSDR reception(2) http://websdr.pa3weg.nl 23
www.delfic3.nl pa3weg@amsat.org 24