In the next few weeks, Jason and I will head to Croatia to oversee the balloon project of Team Stellar. So far we have been working with the team from afar and good communications are essential. We have email, Skype, Dropbox and more, so communications are good. We have been working with time issues to make sure everything happens in a timely fashion – there is a country wide student competition at stake. The students and their mentors are working hard so everything has to go well.
Our biggest problems are ones that we do not have here in Australia. We are used to having a very big launch and recovery area in Australia with few trees and little chance of water. It has good tracking and good mobile data coverage.
Croatia? Well there are plenty of unknowns for both me and the rest of the team in Croatia. The requirements are to keep the balloon in Croatia. This is hard. It is a small country with an unusual shape. The useful West to East range is only about 300km and it is pretty tight too.
That is Croatia in the map top right. So what are all the red bits? Stuff that we have to avoid! Things that we are not used to in Australia. They are land mines. We cannot afford to have our payloads drop anywhere near them. These are left over from the wars in the area from 1991 to 1995. These mines are still very new and deadly.
So what else we will have to contend with? Snow, mountains, poor Internet coverage, pine forests, unknown APRS coverage to name a few.
We will have all the risky stuff covered including cut-down systems to keep the balloons from going too far. Our best weapon is research. Knowing what the upper winds are doing is key to having the best chance of keeping the balloon in the country. We have a few resources to consider. Some we have already told you about.
I will be using the Jet Stream weather links for Europe:
Another is the historic movement of the jet-stream – basically you can get a feel for what is coming
Finally some prediction software from HABHUB – this set up for our project and Zagreb, but you can adjust for your own needs.:
I am now keeping records for the Jet Stream in Croatia each day (I missed yesterday). This will show us the main issues with the winds and how they flow. We have already found major differences between Australia and Croatia with total reverses in the Jet Stream over long periods. Australia seems far more consistent, but Croatia is closer to the northern boundary of the system that determines the winds, compared to where I launch from in Australia. Here in Australia we are further away from one of the jet Stream boundaries. I will post more on that soon.
Here are the records for three of the last four days. I will have a month of records to get to know the way this all works.
The Z shape is common the many flights with the change in wind direction as the balloon rises from the Jet STream to the Stratospheric wind. Once the balloon bursts, the payload goes back through the same winds and the same eind directions get duplicated. It comes down faster, so the tail is a little shorter.
The prediction of the 4th day is a very good on for an easy recovery. It stays well in Croatia and away from the mines and can be launched from Zagreb. Simply we would not launch from Zagreb as we have little control of range. I only use Zagreb as a reference to see where the balloon will end up and the conditions that control the wind directions.
Balloon Launches in a New Country can be a real problem – even across a big country. Take care and research things well.