Another day. More sun. And more probes.

Initially, the RS41 was predicted to land in Ostfildern. I decided to start at the TV tower, track the probe from there, and see how things would develop. En route it became increasingly clear that the probe would land somewhere near Gerlingen.

I changed course and set sail for Gerlingen. The balloon burst. The prediction  shifted to Ditzingen. All right then, on to Ditzingen. Close to Ditzingen, the prediction became Höfingen.

I went there and found a nice tracking spot at the edge of a field. The balloon moved closer, and with it, the prediction shifted back to Ditzingen. So I moved again, and found another equally nice tracking spot next to another field. Here the probe was supposed to land. I tracked and waited. The prediction sort of stabilized but continued to move slowly to the South towards some railroad tracks. The probe would pass my position shortly before landing. www.wetterson.de now had lost the signal, so I entered the positions I received into google maps. The probe moved in a big rectangular pattern over Höfingen and then back towards my position. I tried to spot it, but it was still to high. I readied the camera of the mobile phone. Around 1500m altitude, I should see it now. Nothing in the sky. But wait, there is this small white dot. Camera rolling. Slowly and majestically, the probe on the parachute glided by. The rest of the balloon was fluttering in the wind.

Flyby and Landing of the RS41 started in Stuttgart - Careful guys, 90 MB. Below the parachute and the rest of the balloon there is often the probe itself as white dot near the lower frame of the movie visible.

Touchdown. The signal was still audible and decodeable:

[11308] (N3430005) So 2018-03-25 13:28:04.000 lat: 48.81802 lon: 9.04655 alt: 373.37 vH: 0.5 D: 177.6° vV: 0.1 # [00000]
[11309] (N3430005) So 2018-03-25 13:28:05.000 lat: 48.81802 lon: 9.04655 alt: 373.33 vH: 0.0 D: 289.7° vV: 0.0 # [00000]
[11310] (N3430005) So 2018-03-25 13:28:06.000 lat: 48.81802 lon: 9.04655 alt: 373.16 vH: 0.1 D: 209.1° vV: -0.1 # [00000]

The probe came down near a railroad bridge. I jumped in the car and went there. The bridge was arching over a little river in a deep valley with steep and abrupt cliffs. The signal was strong, but the probe itself remained hidden. I realized that the probe was probably no more  20 m away. I was however on the bottom of the valley and the probe above. The cliffs were way too steep to climb up. I went back to car, studied the terrain. I would need to drive around 3.5 km to reach the edge of the valley from above. The probe seemed to be near a house that looked like a holiday cottage. The probe was still transmitting, so the proud owner was probably not at home. Good.

Close to the landing zone, the road became muddy. I parked the car and continued by foot.

The probe was indeed next to a holiday cottage. I could not see the parachute however. I pulled on the string of the probe hoping that this would also reveal  the parachute. There was only little resistance. The parachute was not attached to the rope. I wound  up the thread and then went towards the cliff looking for the chute and the rest of the balloon. I could not find them.

What I found however on the bottom of the valley, right where I had stood about 20 minutes ago,  were three guys with antennas obviously looking for that what I had just recovered. The river was pretty noisy so communication was difficult. We switch to radio, exchanged call signs, web  and email addresses, and names.

Back at the car, I proudly presented the probe to family that had its cottage right  next to the car parking. They seemed astonished as they did not know of the existence of weather probes at all.

Driving back to Stuttgart, I thought a little bit about the possible whereabouts of the parachute. Maybe, it had fallen on the railroad tracks or even worse onto the catenary. Looking at the trajectory shortly before impact, and knowing that the probe hits the ground first, this is likely. 15 kV are way more than what is need to kill a human being. The thread of the probe should be non-conducting  — but still not a good idea to try it.

When I had been under the bridge, a train had crossed it. If the parachute was indeed on the tracks, the train had certainly dragged it away.  The end of the probe’s thread is a bit blackened. This could be metallic abrasion from the train tracks or the wires of the catenary.

So now, that I have a couple of probes recovered and have even witnessed a touch down of a probe, what is left there? Where do I go from here?

• Recovery of DFM09 if one comes near
• Recovery of an ozone probe if one comes near (I should consider holidays in Belgium :-))
• A night hunt
• Launching a self build probe.
• And cool would be an optimized tracking gear giving more situational awareness — in particular a program that combines receiving, decoding, showing the track, the latest predicted landing site and the own position running on a small computer like a raspberry pi.

Update on 2018-04-03

Jürgen (DL1WN) produced a little movie to share his experiences of the probe hunt. He has kindly shared the link with me: