Intelligent falling, redux

A few weeks ago, the makers of water-rocket launcher the Aquapod sent me a review copy of their device. It's a plastic tripod with a bike pump nozzle and a pressure valve to prevent your pressurized water bottle from exploding on the launch pad. A string and simple latch hold the bottle in place, and a tug launches the bottle up to 100 feet into the air.

One fine autumn afternoon, several of my NCSE colleagues and I headed out to test the Aquapod in a nearby park. There's nothing like people fussing around with strange equipment to draw a crowd, and we soon had a dozen or so people, ranging from about 4 to a few early teenagers and several parents, watching the test. After the first successful launch, all the kids wanted a turn, and many swore they'd ask for one as a present this year.
As you see in the video above, put together by my colleague Steve Newton, there were some technical difficulties along the way, but once we got a low enough angle on the string, it wasn't hard to launch repeatedly, and to great joy and amusement by the assembled kids.

When the weather warms a bit, I'll see about disabling the safety valve and refining the shape of the water bottles to improve launch characteristics. This is necessary, of course, to fully test the important scientific insights of Intelligent Falling.

More like this

I don't know if mine was the first like this, but I had one of these in the early 50's. Of course, it was not a water bottle, it was shaped like a standard SF rocket, but used the same principle and gathered the same crowds.

By Gray Gaffer (not verified) on 11 Dec 2009 #permalink

This guy: http://sciencetoymaker.org/ has an awesome circa 1989 page with, among many other great things to build, a simple and easy to make one of these devices. But his is an overhead launcher (you hold it on a short pole), to prevent it from launching into someone's face.

Getting a 2L bottle in the face at close range could easily knock out a few teeth. The model you have looks dangerous: it is small and at ground level, and looked like several people were hovering over it as it was pumped up; and it tipped over when you tried to launch it, which could easily cause it to launch horizontally.

-kevin