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Hoyé Hoyé !

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As you might have heard our balloon/gondola flew on the 20th October 2017 during sunrise (around 10 o’clock).  The launch day was an intense day, the countdown started at 4 o’clock and we had to be present to make our preliminary verification. My task was to check if every bolt of each clamps was still under correct torque load so I didn’t really need my brain too much.

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Once the countdown has started, Hercules comes in front of the Dome door and takes the gondola on the launching pad. Once that is done we only had a late access minute that only two members of IRIS could intend, Gustaf and me. In the meantime the software team conducted the regular interference test to check that everything is working fine.

 

Two hours before launch was the beginning of the late minute access (?). Everything went well during the verification, Gustaf was operating and I was crossing each task on the checklist.

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On our way back to the Dome, Dieter Bischoff stopped us on our track. A talkie-walkie communication from our ground station said “IRIS we’ve got a problem, the lower camera does not work”. So we had special permission to stay longer to supervise the rebooting of the system and waiting for the ground station response. After 7 or 8 power cycle the conclusion was clear, the lower camera won’t work.
Shit happens!

The launch&flight of BEXUS 25 and the aftermath

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Anyway the flight was majestueous ! When the balloon was release from its constraints (green truck preventing it to rise), it stretched from its wide conical shape to its narrower conical shape.

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During this event we could hear a very characteristic sound, it was similar to the sound of boatsail stretching from (in ?) the wind, it was ready to sail. The balloon rose gently and the flight train (cable between the balloon and the gondola) gently took its vertical position.

 

The Hercules did not need to change its orientation or advance to release the gondola, it almost seemed like the gondola released by itself and didn’t needed help. The ascent was slow and calm, our balloon was sailing for the stratosphere.

A

Well Earned

Siesta

After the balloon started to fade away in the blue sky our principal software engineer, Edgar Nieto, had to take the important responsibility of monitoring the ground station.

 

Overall everything went according to plan and our science team was already analysing the data during the ascent phase. And other departments had the time to do a well-deserved “siesta”.

Something special happened during the flight, the ascent speed was too slow compared to what was numerically predicated. And that is because the total weight of the gondola was miscalculated and so a lower quantity of helium was used.

 

Because of that our ascension phase took 4 hours but normally it only takes 1 hour and half. Because of this condition our balloon followed the south-east and landed in Finland.

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Comparatively BEXUS 25 flew straight to the East and landed in Finland next to the Finnish-Russian border. We are not allowed to land in Russia and certainly not to fly above it, so it is mandatory for BEXUS flight to land in Finland.

The gondola landed just next to a lake and we were lucky enough to land safely on ground. Hard to believe that our two sensor box and their respective polycarbonate booms were intact after landing !

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From the launch on Friday morning to Saturday in the evening, the gondola made a back and forth trip between Sweden and Finland. Dieter opened the package for us and that gave us the opportunity to do a visual inspection before going to bed.

Though our experiment returned intact the gondola structure did not! It bent on the side where SUNBYTE was clamp. Hopefully SSC will find a way to repair this gondola and will give it a possibility to fly again.

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Overall the launch campaign has been a terrific week, I believe that every BEXUS team had a lot of fun and unforgettable memories. Recently we were disassembling the boxes and checking that everything was alright. The preliminary results seems to be very positive so now the technical departments does not have a lot of work (ouf !) and its time for the sciences division to work hard on the data analysis. I am looking forward to hear more about the analysis and the final conclusion of this exciting experiment.  See you soon.

François Piette
Optics, Mechanics, and Economics
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