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====== The Weather Balloon Guide ======
{{tag>howto}}

===== Technical =====

  * Use a location device as used in the commercial weather balloons so others (Amateurfunker) can go for the hunt as well, Zigbee (proprietary protocol) antenna + ground => bad reception
    * APRS transmitter
      * Pro: www.aprs.fi has an online map
      * Con: you need an A ham license
  * Launch site
    * Have a plastic foil to put your balloon on so it doesn’t burst prematurely.
    * Keep an eye on the wind and put your balloon in the middle of the foil. Also support it with your hands (use latex gloves). It won’t lift instantly so you need to keep it on the foil. Keep it away from people and trees after it lifts.
    * Secure the balloon from flying away e.g. with zipties and some string. The neck part was the most robust and allowed to attach zipties. From there we secured the balloon to the heavy helium gas bottle.
    * Put the gas hose into the balloon neck and secure both using e.g. zipties. You can also attach the rope there already.
    * The balloon can be closed with zipties around the hose. Make a u-shaped form with the hose and close it with the zipties .
    * Use a good cord, our first rope looked great but always tore when making a knot. We were happy to use very robust cord from an commercial weather balloon
    * Have a strategy to attach all the things to the balloon. We put a rope directly through the mid section of the parachute linking the gondola directly to the balloon with the parachute in the middle. We did so because the parachute is already deployed, just waiting for the balloon to burst. We did not know what would happen to the heavy remains of the burst balloon. Luckily it did not make the parachute collapse. But the gondola came down with 9m/s (32km/h) which is a bit fast. Landing speed was about 5m/s (18km/h).
    * Use a pressure reducer + rubber hose
    * Have your pump-in gas volume calculated and be sure to have enough pumped inside [[https://docs.google.com/spreadsheets/d/1MblY0bCmwMEz4T__DaKM_QBpSOoHud-_aUi_BMIGSsM/edit?usp=sharing|excel sheet]] or have a spring balance to measure how much you put inside.
  * Balloon:
    * Our balloon wiggled. We have some rotation in the gondola. I was told by a ballonist to add small paddles as dampeners.
      * Pro: can dampen
      * Con: can also be a rotor.
      * Your decision! :)
    * Carbon tubes (even 2 x 1mm x 1000mm @ < 2g) serve as good boom for your mascot or sensors
      * How about bringing your own mascot (since we omitted taking the famous dickbutt - how about you do it)
    * It gets quite cold the higher you get (speak minus 50°C is no problem) so it is a good idea to have your electrics - especially the batteries - inside some thermal insulation
      * Styrofoam works wonders
      * Also - the cpus do work quite good as heating sources - so do your regulators and batteries if your power draw is adequate.
      * No need to take too heavy batteries along the ride
      * Test your equipment inside your freezer @~ -18°C to get some idea if you are on the right track

===== Social =====

  * If you can / if law allows, have a launch location with access to the public. It is easier for you to plan it and you can invite people.
  * Invite people to your launch. It is awarding to see people interested in what you do. A big balloon ALWAYS attracts kids and parents are forced to come. Kids are attractors!
  * If you invite people, be there on time. They deserve it and it is disrespectful to be late.
  * Spend enough time with the people and answer questions. You will experience that even then people will help you on location - last minute.
    * The audience tends to shoot a lot of photos and videos. Have a cloud pace for it
    * Give those people your contact information. Have flyers or business cards. If you just tell an url, they will forget!
  * Have something for all teams! Work hard together and party hard together! Have a pizza meal. Prepare a celebration event at the end. Even a balloon loss is a success.
    * We had sparkling wine and popcorn.
    * We watched the recorded video together and ate Indian food.
  * Have a video! Even though you just want to do science, have a video for sharing and for later presentations. People like science, but they relate to your scientific goals better if you have a video also


===== Planning=====
  * Project /  Mission
    * Have goals, formulate clear goals in the very beginning, stick to them!
    * Every party willing to be part of the flight needs to know and work towards the common goal
    * Have a mission statement
    * Have clear rules and conditions
    * Stick to the goals for the benefit of all
    * Working together is awesome. It motivates people to achieve the goals and work together. Set clear goals together and make them clear.
    * The mission statement is the common essence for all parties. Formulate it in one sentence like “We will fly a balloon for recording a video of the earth curvature, for sharing the remaining place for other $science purposes, on $date, to release the data under $opensource licence to provide knowledge to everyone. Everyone can join the flight until $time.
    * It sucks to be mean, but the balloon will fly with the hardware as it is after the deadline. There is always another ride another day by another team!

  * Technical
    * Ask your regional air control for allowance. [[http://goo.gl/TLU0kq |Deutsche Flugsicherung were cool and helped a lot]].
    * Predict more than you expect! We simulated flight routes for 6 burst altitudes and we were lucky the 3 option was close to our route. Just be prepared predict.habhub.org/
    * Have a checklist what you need to do!
    * We lost a recording because we didn’t check the sd-card. It didn’t have enough space left and stopped after 3 seconds.
    * If you need a GPS fix, wait for it!
    * Have redundancy, where you need it.
    * We had 3 ways to find our balloon during the balloon hunt. 2 failed. We were damn lucky!
    * Ask people who know how to do this and help you
    * Balloon hunting was more difficult than expected. Next time, we will ask ham radio people receiving our balloon and also help hunting it (aprs transmitter and www.aprs.fi for an online map)
    * Document your project, (if need be: afterwards). Documentation or it didn’t happen!
    * On the crash site: document how it landed before you touch and move it.
    * Have an eye on weather. Do it regularly: the evening before, some hours before the launch, on location. It can change any minute. Losing your balloon is sad, postponing the launch is not. More time to celebrate and talking with people.