Air Rockets

This project was so much fun! Jesse and I wanted to build something interesting for Penelope’s birthday party, and I came across this while flipping through an issue of Make Magazine. (You can see some of it online here.) It worked great. We tested it at our Art Playgroup on Friday, then ran it at the birthday party.

The basic design is a 2″ PVC chamber that is pressurized using a bicycle pump, then the pressure is released with a switch hooked up to a garden sprinkler valve, releasing the compressed air into your rocket and shooting it satisfyingly up into the sky.

The rocket construction is pretty basic, just a rolled tube of paper, with a pointy nose fashioned somehow at the tip. You can go fancy and add fins for stability, and the pointier the nose the better, but even the ones that just have a bit of tape at the bottom and top and a flat nose cone still fly. So this is really accessible to any age. Plus you get to experiment with air resistance and drag and pressure and (loudly) counting backwards before pushing the launch button. (Important for warning people they are about to get pelted.) Educational AND exciting!

And of course stickers [don’t] make your rockets fly higher! More stickers!

The kids could pump it up themselves, so this was awesomely self-running once it got going. Our bicycle pump must have about a 1″ cross section area, because the kids seemed to be able to pump it up to about their weight in PSI, which was great, their rockets went 20-50 feet into the air, and we didn’t need to worry about them blowing anything up, unlike their parents who also had a great time pumping it up until the solenoid started leaking around 80-120PSI and blasting their rockets several hundred feet into the air.

Or intentionally making their rockets out of wet napkins just so they would explode…

Which leads to the total devolution of ‘rockets’, here is Rebecca shooting off her stuffed rocket by jamming the tail into the end of the launch tube. They totally flew. You can launch anything from this, and we did. Candy, glitter, water, and, um, falafel. Go Spencer, you know how to party… 🙂

The glitter was really beautiful, but the water was equally squeal worthy and much easier to photograph! The party ended with the adults sitting in the shade and the kids running back and forth pouring water down the launch tube, pumping it up, and squealing as they made it explode into rain all over themselves. Luckily no one was electrocuted by wet batteries. The next revision to the design is to seal the batteries (for the solenoid) in waterproof tupperware…

All in all it was an awesome Yashfest 3 / Penelopalooza 2. Heck if I know what we’re going to build next year!