Tag Archive | delfi-c3

Hope Oscar 68 (XW-1)

I have yet to hear from Delfi-C3 again, but in the mean time below is some CW telemetry data from HO-68 decoded with MixW on Friday (10 June 2011). According to one of the Delfi-C3 team members the CubeSat’s transmitter drops out intermittently and functionality is only restored once the spacecraft goes through eclipse and resets (Delfi-C3 has no batteries on board). Cape Town is its last `stop’ before the spacecraft goes into eclipse again so the likelihood of its transmitter having dropped out by the time it is over head is large, I guess.

I have also experienced quite a bit of interference around 145.870 MHz, the frequency at which the primary telemetry downlink is for Delfi-C3.

I have still to try and decode the messages below, but here they are in anycase. Most of the payloads on HO-68 is non-operational but the CW beacon is still active at 435.7900 MHz.


In the next week or two I will try to start setting up our two TNCs and find some satellites with active data/packet payloads to test them. I might also start posting some information and pictures on our equipment and current setup. Last week we also received our SignaLink USB sound card.

First contact

I guess it is about time to get things going. The ground station at F’SATI has reached a point where we can start to track satellites. There is however quite a bit work still to be done. One of which is to check that we are actually pointing in the direction we are pointing in 🙂 . SANSA Space Science (former HMO) in Hermanus was kind enough to lend me a proper nice magnetic compass, so I will probably be aligning our antennas to north in the next week or two. Even with the not-so-accurate pointing we have been able to successfully tack some satellites. Most of these however were morse (CW) beacon payloads. That is, until Friday.

Friday I decided to try and see if I could get some telemetry data from Delfi-C3. I was not very optimistic because up to that point we have not had much luck receiving telemetry data and the maximum elevation for Friday morning’s pass was only 26°.

So with SatPC32 and RASCAL fired up I started tracking the pass. The point of maximum elevation came and went without so much as a peep and with the CubeSat starting to move closer to the horizon I resorted to manual adjusting of the radio, rather than having SatPC32 do it.

After a bit of fiddling and tuning we started to hear the distinctive sound of telemetry data over the radio, but no decoded messages were showing up in RASCAL yet. So more fiddling and tuning was needed. By this point the satellite was getting pretty low on the horizon and I was about to give when two telemetry messages showed up in the little terminal screen of RASCAL.

We had successfully received our first telemetry data from a CubeSat using our newly constructed ground station!

And with that the first pass/tracking report was sent off from F’SATI to the Delfi-C3 Team in the Netherlands. I was quite impressed that we were able to track Delfi to almost on the horizon with our ground station (LNA’s enabled). Here are some of the datails:

Our location:   JF96HB (33° 55′ 55.6 S 18° 38′ 35.8 E)
AOS (Acquisition of signal – start of pass): 08:55 UTC
LOS (Los of signal – end of pass): 09:08 UTC

Primary telemetry downlink frequency near LOS: 145.861 MHz.

M² Antennas (VHF/UHF): 2MCP22 and 436CP42
Advanced Receiver Research LNAs
Icom IC-910H transceiver

And the telemetry data received via RASCAL looks a little something like this:

from: DLFIC3 to: TLM    a8 98 9b 40 40 40 00 88 98 8c 92 86 66 01 03
f0 e1 08 a0 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 01 00 01 00 01 00
01 00 01 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 c3 a6 00 00 00 00 4e 5e 01 1d a1 05 a9 7b 52 00 03 63 60 1e
00 00 00 00 00 00 00 00 00 00 50

As far as I can tell this is telemetry data from the AWSS (Autonomous Wireless Sun Sensor) payload on Delfi. Hopefully we’ll be able to get more data on the next attempt early next week.

Ground station - mast and antennas

Ground station - mast and antennas