A device will be built to achieve the goals of Project Phoenix. Its task will be to record by means of an HD camera a part of our planet and the blackness of space which is surrounding it. This device will consist of three main parts:
1. carrier (meteorological balloon)
2. parachute (ensuring soft landing)
3. capsule (containing all the electronics)
Picture. 1: Sketch of device
The helium-filled, meteorological balloon is capable of carrying the capsule up to a height of 30 km. Helium has a lower density than air, so the higher the balloon ascends, the lower pressure will be on it (see Picture no. 2 – spot 1). These two facts cause a slow increase of the balloon´s size until it bursts at a height of around 30 km.
The meteorological balloon, weighing 1,5kg and capable of bearing a load of up to 1kg has just after filling the size 185 cm at its diameter. After reaching its maximum height of 34.2 km its size is already 944 cm in diameter. The pressure in this altitude (6.3 hPA) then ensures that this overinflated balloon bursts (see picture 2 – spot 2).
After a few seconds of weightlessness, the whole load starts falling back to earth. The acceleration will activate the parachute, which was originally suspended under the balloon. The parachute ensures that the probe falls to the ground at an appropriate speed and with no damage to the content (see picture 2 – spot 3).
Picture no. 2: Sketch of the flight
The successful flight of Phoenix itself is only the first part of overall success with the project. The second part is the correct functioning of the capsule’s content, which will be made of hardened polystyrene, painted black to absorb more sunlight and thus accumulate more heat, and partly wrapped in aluminum foil (to make it more visible to pilots). Its shape will be designed to hold the camera in a horizontal position during flight, ensuring that it does not rotate so much and that it remains in a constant position during downfall. This brings me to the most important part and that is the content of the capsule. This will consist of a small full HD camera with a battery able to run the camera for the whole flight (ca 110 min) as well as a GPS device, which will be sending information about the location of the capsule. This information is crucial for the retrieval of the capsule after landing. If the weather is on our side, the landing site should be within a 100km range from the release location.
Since the temperature in the stratosphere ranges from - 45 to - 75 °C, which the capsule must survive and since there can be airstreams with a velocity of several hundreds of kilometers an hour, the technology and especially the batteries must stay warm. That is why the capsule must be perfectly sealed. In addition, hand warmers will be placed in the capsule.
If we manage to get enough money for the realization of Project Phoenix, the capsule will be improved by ShadowBox, which will be able to record many very important details during the flight – temperature, velocity, flight trajectory, etc. and the second camera, which would be placed vertically at the bottom of the capsule. Appropriate approval for the flight by the Air Navigation Services of the Czech republic will be obtained if required.
