Joe Talento's official title at the Franklin Institute is traveling educator.

Unofficially, he is a bit of a mad scientist.

On Friday, he gave an explosive preview of the seventh annual Philadelphia Science Festival, firing plastic bottle rockets from the front steps of the museum on the Parkway.

The nine-day festival includes more than 80 events at museums, schools, parks, and other venues starting Friday.

Asked what type of propellant he was using, Talento was circumspect.

"Right now, I'm going to keep that as confidential," he said. "We don't want people running out and blowing themselves to pieces."

He fired off a half-dozen rockets, each time spraying a shot of propellant into the bottles, then blowing in a puff of air to add oxygen to the mixture. He launched the missiles with a handheld igniter similar to the kind used for a backyard barbecue grill.

"Sometimes it really is rocket science," he joked.

Then it was on to the inside of the museum, where three of Talento's colleagues used liquid nitrogen to launch a pair of garbage cans full of plastic balls.

Elsewhere, museum astronomer Derrick Pitts was expounding on matters celestial, while others demonstrated 3-D printing machines in the institute's new Tech Studio.

The festival concludes  April 29 with a science carnival at Penn's Landing, where Talento and colleagues plan to launch 100 plastic bottle rockets similar to the ones he demonstrated on the museum steps.

The full schedule can be found at