2018-06-03: The Probe of Aichschiess

Arriving from the ham fare in Friedrichshafen at 1:00 am, the coffee that I had drunken in Friedrichshafen to not fall asleep during the drive, still kept me going. I was not tiered at all. The probe had just started and the prediction put the landing zone north of Esslingen. I watched TV and cranked up the receiver to track the probe. Shortly after 3 AM, I received the last telemtry package. By that time, wetterson.de and the aprs network had already lost the probe in 3064.000 meters and 3560 meters altitude.

[ 9881] (P0620647) So 2018-06-03 01:03:49.000 lat: 48.74976 lon: 9.41519 alt: 753.92 vH: 3.3 D: 157.1° vV: -2.5 # [00000]

753 meters altitude with the ground at around 480 meters, i.e. around 270m above the ground. Not bad. The gps coordinate were however over a forest, so the probe would likely hang in a tree.

 

Ground track of probe

 

The next morning, I decided to go after the probe. Nearing the landing zone, I received and decoded its signal — assuming that the probe was powered up at 0:40h in Stuttgart, it was still up and running  9 hours 40 minutes later.  And the probe had indeed fallen into the forest. I parked the car and continued by foot to its final destination:

[36159] (P0620647) So 2018-06-03 08:21:47.001 lat: 48.74917 lon: 9.41441 alt: 405.64 vH: 0.1 D: 245.0° vV: 0.0 # [00000]

 

Ground track of probe during the final phase of flight

 

Path into the wood

 

Off the beaten tracks and into the underwood

Half an hour later, I had reached the gps position of the probe. Looking around, I found first the thread shimmering in a tree and then the probe. It was hanging  in about 5m height. The parachute was somewhere in the foliage and I could not see it.

 

The tree in that the probe landed. At close look, the thread of the probe is visible.

 

The probe in the tree

 

Probe barely visible in the foliage

 

As the tree looked reasonably stable, I decided to give it a try and climbed up — something I have not done for quite a while.  10 minutes later, I had reached the probe. I checked the radio. The probe had stopped transmitting — the batteries had lasted for around 10 hours 15 minutes. Hoping that I could also recover the parachute, I started to pull carefully on the thread. The parachute became loose, but after 2 more meters the thread was stuck. The parachute was entangled somewhere in the tree. I had no choice but to tear off the probe. It took me another 5 minutes to make down from the tree.

 

The probe just an arm length away

 

High on the tree — Oh! c’est haut, c’est haut

 

Myself and the probe after I was on solid ground again.

 

I then went back to the car. Midway I found a raised stand, climbed up to rest a little bit and to disentangle the thread. It was there, that I realized that the probe is a new variant. The electronics are identical to the RS41 I had already collected. The casing was however redesigned and is now manufactured of styrofoam. The plastic casing has vanished. Apparently, Vaisala has done some value engineering to further cut the production cost and reduce the launching cost by lowering the weight. This explains the different format of the probe id, i.e. the id string transmitted starts with a P rather than the N.

Enjoying to walk in the forest, I strolled a bit around before returning to the car and ultimately to Stuttgart.

On the raised hide