On June 17, 2021, the long-awaited day had come, BUBBLE 2 could finally launch after a year’s delay due to Corona!
30°C outside temperature in Stuttgart and the team gathered, with negative Corona tests, at the university in Vaihingen to do the last preparations for the balloon launch. Changing batteries, preparing the ropes, gondola and parachute and to finish setting up the ground station. In the process, the software from the mobile ground stations still had to be set up on enough laptops so that tracking of the balloon was possible in each of the three tracking cars.
Around 12:30 the preparations were finished, all things were packed and the gondola and the helium were brought to the launch site. There the team set up a pavilion for some protection from the sun and started to assemble the gondola and check all the functions. At the same time, the balloon was filled. Shortly before 4 pm everything was ready and BUBBLE 2 was launched.
A flight time of roughly 3 hours was calculated with an approximate landing site north of Bretten. On a windless day the balloon does not fly too far away, which makes the chase more comfortable, so there was enough time for cleaning up, filling the water bottles and eating an ice cream before setting out. Using the tracking systems integrated in the gondola, the position of BUBBLE 2 could now be pinpointed and the flight route followed. Both the mobile and stationary ground stations were able to receive good data. At an altitude of almost 36km, the balloon burst and the gondola fell in free fall until the parachute was able to brake in the denser atmosphere. BUBBLE 2 glided gently to the ground at 5 m/s for the last few kilometers. The cars drove to the approximate landing site from different directions to increase the chance of recovering the gondola quickly. This is important if, for example, there is a river nearby to be able to rescue the systems in time.
All three chase cars had gathered near the expected landing site shortly before the landing and one of them could even watch the gondola descending. It was an unspectacular landing in the field, far away from roads and towns and during recovery no damage to the gondola or electronics could be detected. So it was a successful flight.
The entire flight was filmed by our GoPro, provides stunning footage and can be viewed in full on Youtube.
The data evaluation now also brings BUBBLE 3 a lot further, as we now know which of our systems worked well and where there are still weak points. Our goal to develop a plug-and-play system for high-altitude balloons, has come a lot closer this day!
BUBBLE 2 gondola is being prepared for launch test of the ground stations with the water canister the lift is measured balloon being filled with helium liftoff balloon with parachute, gondola and radiosonde shortly after liftoff Campus Vaihingen Stuttgart, Vaihingen and the airport Autobahn intersection Stuttgart and Böblingen/Sindelfingen airplane condensation trail of the airplane Stuttgart from ca. 15 km altitude the river Neckar and the city of Heilbronn thunderstorm during ascent shortly before the burst of the balloon at 35 km altitude balloon bursts at 36 km altitude radiosonde at the end of the red rope gondola and radiosonde in free fall thunderstorm during descent a few minutes before touchdown visual contact to a chase car shortly before touchdown touchdown in a field parachute in the field successful recovery gondola after successful flight the BUBBLE team after successful recovery
