Millau 2002
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The Larzac camp is located in the South of France near the town of Millau, famous for its viaduct.
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The International Space Festival 2002
I'm not going to rewrite everything about this festival, but to summarize very succinct I would simply say that it is the launch campaign rocket clubs organized by CNES and Planete Sciences (ex- ANSTJ)
For more information, see the Planete Sciences website:
http://www.planete-sciences.org/espace/index.html
I went there, not only to see and support the Cles-Facil which launched no less than 3 rockets (two minis and a fusex), but also to launch a some water rockets including a two-stage. It is of course of those which I will speak about here, leaving it to Planete Sciences and to the clubs concerned the care of exhibiting their achievements.
My launches
I made three shots, MiniP a 0.5 liter, Panache also 0.5l and the two-stage.
MiniP was launched from the Parc de la Victoire in the center of Millau, where the club stands and the water rocket workshop were located for the very young. As the launch took place in the middle of the trees, I put a minimum of pressure (around 4 bars). Perfect flight and opening of the parachute, with of course landing in a tree. It took a large scale to retrieve it.
Minip: I don't have a photo of the launch.
Panache, launched from the Larzac military camp at 9 bars. Flight and recovery perfect. I did not measure the altitude, but it climbed very high since I could no longer distinguish it at the culmination.
Installation on the ramp and explanation about the ramp and
the aerodynamic flap recovery system.
The pressure is on, take-off imminent ...
And There
take off
The 2 stages
The two-stages, made up of "Cacao" on the first stage and "Orlime" on the second. Cacao is a 1.5 liter double and Orlime a 0.5 liter double. Each stage has its own recovery.
The stage separation system is modeled on that of Bruce Berggren, ie the 2nd stage nozzle is a rigid tube 8 mm in diameter and approximately 6 cm long. This nozzle is fitted into a flexible plastic tube (Vinyl) with an internal diameter of 8 mm. This Vinyl tube is fixed on the upper stopper of the first stage, while the other end is closed by a valve which allows air to pass in the first direction towards the 2nd stage.
When the pressure is the same in the two stages, the friction between the "nozzle" and Vinyl tubes causes the two rockets to remain solicited. When the pressure in the first stage decreases, the pressure differential tends to "inflate" the vinyl tube and therefore to reduce the friction between the two tubes, to the point of freeing the second stage.
Below is a view of the assembly
When pressurizing (above), the second stage (Orlime) started to leak at 3 bars at the junction of the two bottles. I had to replace it with Panache (below).
This time, it is the first stage "cocoa" which started to leak but at 5 bars. That's enough pressure to launch, so let's go to this pressure.
The separation was done perfectly at about 40 m (estimate). The parachute from the first stage exited but did not open, resulting in a rapid descent and a violent landing. This first floor is therefore dead, anyway it was leaking, so the loss is not too hard. The second stage Panache again worked perfectly and was recovered without damage.
