Tuesday, December 10, 2013

Bored? Hack your own satellite.

Many tiny satellites have been launched a short while ago and most work as planned. Only one little Cube-sat was lost.
Its makers (4 German guys in a garage) called it WREN. Its workings are simple. It snaps pictures with its camera on command and sends it down with SSTV on the 70cm band by command. Its like having a wireless web-cam in space. A real cool web-cam.
Only....., this one got lost. Its somewhere up there al-right but there is no signal where its makers, now slowly getting depressed, search for one.

Now its makers ask us to help them out and get things going again. So here it is.
How to hack your own satellite.
Use it to photograph .... well anything from way up there. Maybe make a snapshot of that UFO you know must be out there. Then send the data down to your computer and share it with the world.

WREN

The frequency this baby runs on is 437,405 MHz +/- 10 kHz Doppler-Shift where it sends its pictures in SSTV and also has its uplink.

Its location is erm.... somewhere around the earth.  (They hope.) There are some reports of amateurs that heard WREN but its appearances  are shrouded in mist.

To announce it is there, ready and waiting, the satellite sends 1.6 seconds in AFSK. This sounds like: " pipipipipipipipipipip". Then it waits for 6 minutes for a signal.

UB4UAD screen-shot of WREN signal received Nov 26, 2013 at 06:47:13 UT

The signal is simple and any HAM can do this. It waits for a silent FM signal and Morse-like code. (So just keying the mike by hand will do.)

1 = long    0 = short

110011 = Activate (wait for answers within 2 seconds)
11111 = Camera on
110 = Snapshot/Thumbnail (make image with 12x14 Pixels)
110100 = SSTV send in Mode Martin-1 with 320x240 Pixels
No, there is no self destruct code.

Now first activate, then put the camera on, then make the snapshots or full size pictures. If doing it the wrong way around the satellite goes to sleep mode. So don’t mess this up.
By the way, you’ve got about ten to max 15 minutes to activate, turn on camera and download the image, before the cube sat is out of reach. Its not only the coolest web-cam, its also the fastest one.

Don' t forget to contact those Germans and lighten up their day.

More info at:
http://amsat-uk.org/2013/10/24/wren-a-ham-radio-sstv-pocketqube/
https://www.facebook.com/StaDoKo

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