PROJECTS: AIR ROCKET
PUMP IT UP, UP, AND AWAY!
AIR ROCKE T ANATOM Y
1 Bicycle pump
2 Tire valve Allows PVC chamber to
3 ¾" inline electric sprinkler valve
Releases the pressure in an instant
4 Paired wires Connect the battery
button and sprinkler valve.
5 Button Triggers the sprinkler valve
for the launch.
6 R/C toy or power tool battery
Provides the juice necessary to
trigger the valve under pressure.
My 5-year-old son demonstrated the
physics of an air rocket recently at a
hamburger joint when he shot the wrapper
off his soda straw. That’s basically how
this air rocket works.
The launcher is made from PVC pipe,
and has a chamber that’s pressurized using
a bicycle pump. The pressure is released in
a split second through an electric sprinkler
valve, sending the paper-and-tape rocket
into the sky.
What’s unique about this design (as
opposed to a solid-fuel model rocket or
soda-bottle water rocket) is that the force
of the air propelling the rocket upward is
applied all at once. It still blows my mind
that just this initial blast of air can send
the rocket so high.
If you want more info on the basic
physics of the air rocket, this NASA link
gives a nice simple description: makezine.
com/go/airnasa. NASA’s description of how
air-powered rockets work also includes a
nice Flash animation.
Illustration by Nik Schulz
104 Make: Volume 15