As expected, we are on a steep learning curve with the new project, but we have been doing a bit of background research over the last 3 months or so to come up to speed.
We have been researching the following –
Balloon Suppliers – Kaymont in the US seems to be the supplier of choice for latex weather balloons, so looks like we will need to import some balloons, we might need to get a few in case of mistakes … We will probably start off with the smaller ones and see what issues we have with CASA and bigger balloons.
Balloon Filling, Weighing and Launching – We will need to develop a rig to fill the balloon, as well as a spring scale to measure the amount of free lift the balloon has. We will need to work out how we will launch the balloon without it tearing or getting caught in trees / fences etc.
Balloon Trajectory Forecasts – There are a couple of websites we have found that can predict the path of a weather balloon. One is run by the University of Wyoming in the US and another by Cambridge University in the UK. These use weather forecasts from the global forecasting system. Whilst they wont be 100% accurate, they should give us a guide to calculate our launch site so that we can land the balloon roughly in nice farming fields rather than in the pacific ocean or deep in a ravine in the Great Dividing Range.
Helium Suppliers – We have some local suppliers including BOC gases, Speedgas, AirLiquid, Supergas .. we will just need to talk to a few and see what prices we can get and what handling training we need to transport and safely use the gas cylinders
Balloon Tracking – We will use two different methods to track the balloon. Both will utilize gps locations. The primary tracking method will be utilising amateur radio to broadcast the gps co-ordinates via aprs. With an aprs equipped radio in the chase car we will be able to get the gps co-ordinates directly from the balloon as long as we can hear it. Also other aprs enabled radios within range of the balloons track will be able to pickup the gps co-ordinates and upload them to a website (http://aprs.fi) so it can be tracked on the internet. We need to make sure we get a gps receiver that works above the normal 60,000ft ceiling. Byonics have once called GP4 specifically for high altitude balloons which works up to 84km in altitude.
The secondary tracking method is a SPOT, this will provide gps co-ordinates to overhead satellites and update the balloons location every 10 minutes. This is really useful on the ground after it has landed in case we have primary tracking failure or cant find it. It also updates the location onto a website.
Amateur Radio – As we will be transmitting radio frequencies we need to get an amateur radio licence and callsign. The first license we need to go for is the Foundation Radio License. Both Mark and I will attend a training course and sit the exam. Due to the radio being mobile we may also need to sit an additional test for the next license up which is the standard license.
Civil Aviation Safety Authority – We need to make sure we stay within CASA’s regulations and already we have read through quite a bit of their documentation. Looks like we need to limit the size of the balloon, fly a radar reflector on the balloon as well as get a NOTAM (Notice to Airmen) clearance on the day of the launch. We will need to do more work on this matter.
Cameras – We have a bit of experience running multiple cameras on our vehicles from our previous projects, so we will launch with several cameras. We will utilize our existing MD8o cameras, we will also use a GoPro Hero2 Camera on board. These cameras are HD and will hopefully provide us with the amazing video of the curvature of the earth and the thin layer of the earths atmosphere.
High Altitude Testing – We are working on an approach to testing the payload under low temperature and pressure conditions, we will be looking to build a test rig to place the payloads into that we can fill with dry ice to bring the temperature down to the -50C range to tests our batteries, electronics, radios, cameras etc. We may also adapt a vacuum pump to bring the test rig down to less than 1psi to simulate air pressure at 100,000ft.
As we work through each of the items we will give more detail. Like we said , more research do be done yet