After our first successful test with our cargo flight, it was time to properly put our system through its paces during the first Droptest on Tuesday, 26th of April.
The goal of the flight was system identification. Hardcoded steering inputs were implemented into the software with the hopes that after the flight the collected data would shed light on the flying characteristics of the system. This data will prove crucial in tuning the Guidance, Navigation & Control loop.
It was around 07:30 when all members of team PERIPHAS as well as the HELVETIA recovery team got together in the hangar at IPZ. The mood was not the best. We needed good weather to perform the drop, but it was raining cats and dogs. Little did we know the weather had even worse surprises in store for us. Either way the decision was made to drive up to Wichlen and set up for the test. Constant communication with the helicopter pilots about the weather was important as the helicopter take-off was delayed from before noon to after. Around noon, it started snowing. This further slimmed the chances of a test being conducted, with the weather showing no signs of improvement. These delays proved to be a blessing in disguise as some last-minute software adjustments needed to be made. With the bugs ironed out, the skies suddenly decided to bless us with some sunshine and the helicopter was allowed to take off from Dübendorf. In the meantime, the last assembly steps were finished, and the team eagerly awaited the arrival of the Super Puma.
On the helicopter’s arrival, a briefing was held with the pilots, who gave the mission the go ahead even with some slight cloud cover. Tensions were rising during the helicopter’s take off, with our system attached to it with a longline. We have endlessly worked on this system since September, and now it was making its way up to 900 metres above ground. 3,2,1…Release! Cloud cover blocked the view for the first few seconds. Our hearts collectively skipped a few beats, but suddenly we saw the beautiful black, white and orange parachute inflated with the system hanging below it. A huge relief with things going well so far, but now came the crucial part of the mission: Will it steer itself? You could hear a pin drop as the team patiently waited for the system to make its first turn…AND IT DID! Absolute scenes unfolded at Schiessplatz Wichlen. After the first turn followed a braking maneuver and another turn before it descended gracefully in a spiral. An absolute success…until we noticed the system getting awfully close to some trees.
Graceful descent ended in a rather exciting landing spot as the system hung in some treetops. Fearing the worst, we headed up the hill to assess ground recovery. Wading through muddy, steep and thick forest to get to it the team contemplated climbing the tree somehow and cutting the parachute off. Luckily, we didn’t. We got some ropes attached to the system and pulled furiously. After some collective effort, the trees finally let go of our system and we recovered it with no damage to the system or the parachute! The joy within the team was indescribable!
Data was recorded and saved, and the team headed home from Wichlen with a smile on their faces to get some well-deserved rest.
Next up: Drop Test #2, Monday 2nd of May.
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