Gas Rocket

posted: 04/11/12
Read more Read less
As seen in "MythBusters: No Pain, No Gain"


Explanation: Propane tanks and open fire don't go together like hamburgers and hot dogs. The 5-gallon propane tanks that keep many backyard barbecues cooking are potentially explosive if their temperatures rise enough. The MythBusters even dug up a supposed scenario in which a propane tank burst into flame, igniting the pressurized fuel and launching it, rocket-style, 150 feet (46 meters) into the air.

Tory Belleci, Grant Imahara and Kari Byron blew up a bunch of propane tanks to see whether they could indeed convert a grill into a launching pad. For their first go-round, they set a mock garage on fire to see whether the 800-degree blaze would detonate a propane tank. As suspected, the built-in safety valve automatically released the internal pressure inside the tank once it started roasting, removing any rocket potential.

The team then tinkered with the tank until they found the best way to beckon a blastoff. They punctured a small hole in it, allowing the gas pressure to exit and generate thrust. And since a too-full tank contains no room for explosion-friendly gas expansion, the MythBusters drained most of the propane. Upon ignition, the near-empty propane tank swelled and soared 60 feet (18 meters) into the sky.

Although it took some precise parameters to get their homemade rocket off the ground, the MythBusters' success proved the propane tank myth plausible.

More on