PROJECTS: HHO ROCKET
Each water molecule (H2O) is composed
of 2 hydrogen atoms chemically bonded to
1 oxygen atom. Passing electricity through
the water breaks these bonds by a process
called electrolysis. In our gas generator,
baking soda makes the water conductive,
and stainless steel strainers are used as
electrodes that won’t rust.
Oxygen atoms are freed at the positive
electrode, and they bond with other oxygen
atoms to create stable oxygen gas (O2).
Hydrogen gas (H2) is formed at the negative
electrode. Mixing these gases does not form
water; at room temperature they remain
stable gas molecules. The mixture is known
When it’s time to launch the rocket, heat
from an electric igniter provides the activation
energy to break the chemical bonds of nearby
gas molecules, freeing hydrogen and oxygen
atoms that recombine as the more stable
molecule water (H2O), releasing energy that
liberates more atoms that recombine as water,
releasing more energy, creating a chain reaction.
The igniter is thin wire with a pyrotechnic
chemical on the tip that bursts into flames
when current passes through the wire. A dowel
positions the igniter above the water and into
the explosive gas.
The lower stage (first stage) carries the
ignition electronics that ignite both stages in
sequence, and guide rails that fit into tubes on
the upper stage. When the upper stage fires, its
tubes slide off the guide rails and it flies free.
HYDROGEN-OXYGEN ROCKET — HOW IT WORKS
Illustration by Timmy Kucynda
92 Make: Volume 20