[amsat-bb] Re: Delfi-C3 status update -THANK YOU!!!

Joe Westbrook k7zt at suddenlink.net
Wed Apr 30 10:44:20 PDT 2008

Ok, I've monitored 4 decending passes and have yet to hear anything. Does 
anyone have an updated set of Keps that I could have?

- Joe, K7ZT

----- Original Message ----- 
From: "Stefan Wagener" <stefan_wagener at hotmail.com>
To: "Wouter Jan Ubbels" <wjubbels at gmail.com>; <amsat-bb at amsat.org>
Cc: <rascal at delfic3.nl>
Sent: Wednesday, April 30, 2008 10:43 AM
Subject: [amsat-bb] Re: Delfi-C3 status update -THANK YOU!!!

> Thanks!
> What a great example of keeping the community informed.
> By providing us with a very interesting satellite, a nice software tool, 
> access to data and the opportunity to share in your experiences your team 
> has done a tremendous job for the satellite amateur radio community and 
> the promotion of our hobby and interests.
> Thank you and please keep it up. I am looking forward to tonight catching 
> more telemetry. :-)
> 73, Stefan VE4NSA
>> Date: Wed, 30 Apr 2008 10:16:58 +0200> From: wjubbels at gmail.com> To: 
>> amsat-bb at amsat.org> CC: rascal at delfic3.nl> Subject: [amsat-bb] Delfi-C3 
>> status update 30 April 2008 08:00 UTC> > Hi all,> > Delfi-C3 is in orbit 
>> and healthy, despite some minor issues, please find a> status update 
>> below:> > 1. Telemetry indicates that all solar panels and antennas have 
>> deployed> properly> > 2. Telemetry indicates nominal values for all 
>> housekeeping values> > 3. We have already obtained payload data, and have 
>> been able to generate IV> curves of the Thin Film Solar Cell experiment, 
>> note that those uring> RASCAL can view the IV curves by clicking 
>> Options-->show IV curves in> RASCAL.> > 4. The spacecraft is operating in 
>> science mode, we have had one orbit in> emergency mode, which was most 
>> probably due to a databus issue> > 5. Up till now we have received 7000+ 
>> (!) frames from amateurs using RASCAL> around the globe, amazing, thank 
>> you all so much!!> > 6. We have verified command uplink funct!
> ionality yesterday, and were able to> command the spacecraft today on the 
> low elevation (4.9max) pass over our GS> at 0737UTC> > 7. The spacecraft 
> has decided to consistently use the backup radio on> 145.930MHz for its 
> telemetry downlink, we were able to request a full> on-board database dump 
> while in range of our groundstation yesterday and> analysis of the 
> database confirms this. We currently have a good> understanding why this 
> is the case. We will try to switch downlinks to the> primary radio on 
> 145.870MHz during the next good pass over our GS, so> amateurs in Western 
> Europe might want to check that frequency also and might> experience 
> intermittent telemetry while we are commanding. Note that we> suspect that 
> the TX frequency could be 1 to 2 kHz lower on this radio, so> tuning 
> around slowly is the best strategy.> > 8. The spacecraft seems to have an 
> issue with the downlink TX switching off> into the orbit, which is the 
> reason while Delfi-C3 has not been heard on> most de!
> scending passes over VK/ZL, we think we have a good understanding of>
> why it is. The TX itself is fine, but it switches off automatically when 
> it> does not get data from the OBC for a certain amount of time. We are 
> working> on resolving this issue. This also happened during the pass over 
> our GS at> 0737 UTC but we were able to command it back on. For those in 
> Western Europe> we would like to ask to keep tracking Delfi-C3 even if you 
> can not hear it> at first, as we will try to turn the TX back on as soon 
> as we notice that it> has been turned off.> > 9. Thank you all for your 
> observations on the spin rate, these are really> helpful! We currently 
> think that the spacecraft is tumbling with approx> 10deg/second, which 
> corresponds to a 36 second period. Since the s/c> downlink antenna is 
> almost truely circular, polarization sense can change> from RHCP to LHCP 
> completely depending on s/c orientation, we use circular> antennas on our 
> GS as well, and when we switch to the opposite polarizaiton> sense the 
> signal is wiped out completely, switching back !
> gives solid copy> with strong sigs.> > 10. NORAD object E #32787 seems to 
> match best> > > thanks for all your observations and efforts so far!> > 73 
> on behalf of the Delfi-C3 team,> > Wouter Jan Ubbels> 
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