Launch of a water rocketWater rockets have many advantages over pyrotechnic rockets, although their performance is more limited.

The fact that they are not pyrotechnic removes the risks associated with this technology (burns, fire) and the related legal constraints. In France, pyrotechnic rocket launches must be carried out under the aegis of CNES (the French NASA), which has delegated project control, the organization of launch campaigns and club monitoring to Planète Sciences.

Water rockets are therefore not subject to this regulation, but this does not mean that this activity can take place anyhow, anywhere and without a minimum of precautions as we will see in the chapter on safety. On the other hand, water rocket launches can be done when desired outside of the launch campaigns organized by Planète Sciences, which are on well-determined dates and in limited numbers (May-June for minifusees during the " Festiciels ”or generally in July or August for the national campaign).

Another interest, the water rocket activity is very inexpensive. Most of the matérials used can come from recovery (plastic bottles of soft drinks, cardboard), moreover, the necessary tools are rudimentary (ruler, cutter, scissors). This authorizes the realization and the launching of numerous rockets, therefore numerous experiments.

Unlike pyrotechnic rockets for which we have little control over the propulsion (only the choice of engine is possible), the water rocket allows you to play on many parameters (quantity of water, pressure, nozzle diameter), which multiplies the possibilities for experimentation.

Finally, and contrary to popular belief, we can also embark on experiments. Of course, the altitude reached by a water rocket will be lower, but in the altitude range of amateur rockets this is not really a brake. Better still, the fact that the total impulse of a water rocket being generally lower than that of a pyrotechnic rocket this forces the designers to show a lot of ingenuity and thoroughness to make it lighter while ensuring the resistance to accelerations much greater on a water rocket than on a pyrotechnic.

In this site, we will first discuss the making and launching of a first simple rocket, which will allow you to familiarize yourself with a good part of the aspects of this activity. Then we will deepen the technique of each of them.

In addition, there are many sites on water rockets, each more interesting than the last. I'm not going to list them all here, but the table below gives the few sites that I think are the most important and why they appear to be so.

On the subject: Water rocket

In English

Clifford Heath his simulator is very well done and easy to use. It is the benchmark in the field. Thanks Clifford.
Dean Wheeler Interesting video on the propulsion phase, a no less interesting part on the theory and finally a simulator which unfortunately no longer works, except to go back to an old version of Java
Paul Grosse
Another very good quality simulator and lots of other informations
Air Command Water rockets The most advanced water rockets with many explanations and vidéos

In French

Lots of examples, lots of info. A must see
EricAbgrall Blueprint of a simple rocket
Jean Pierre Laine Very detailed descriptions of the manufacture of rockets and launcher
GoMars Bernard's site who co-animated with me the Planet-Sciences training courses for "Water rocket" facilitators

On the subject: Pyrotechnic rocket

CLES FACIL The club that I created in 1967 with some friends and to whom I owe this new passion.
Planete Sciences The entity which federates and animates science clubs in France.
CNES Rockets "for real"
NASA ditto above, but at the American level.