No this is not woodworking, but it sure is fun!
I subscribe to Make Magazine, and they have all kinds of fun stuff in there.
One of their classic earlier articles is an air rocket system, from issue #15.
This involves rockets made from paper and a launch system from PVC pipe bits and a sprinkler valve.
Here is a link to the makershed where you can buy a rocket kit like this.
It's not that I want you to buy the kit, I didn't buy it myself, mostly since it is out of stock. But they have a nice video there that walks you through building one, and launching it.
Here is what the completed system looks like. There is a pressurized air chamber at the bottom, made out of a section of 2"PVC. Above it coming from a T-connection is an electric sprinkler valve, for releasing the air, and then a launch tube where the rocket is mounted.
Here are two rockets. They're just paper and tape. You can find a download template on the make website that prints on legal sized paper. Took me about 45 minutes of cutting and rolling and taping to make each one. I made one using duct tape, and one with just green masking tape. Both were about equally easy. There is no parachute, it just falls after a launch. They're light enough, though the nose cone might get banged up a bit.
At the one end of the air chamber are some reducers which hook up the chamber to a length of hose. (I need to get some small hose clamps, as the zip ties are NOT strong enough. The hose pops off when you hit 50lbs pressure.)
At the end of the hose you need a bicycle pump. Pick one with a gauge on it, as you need to know how much you have pressurized the system.
The sprinkler valve is the key to making this work. You need a way to quickly dump out the pressurized air, in order to launch the rocket. This is probably the most expensive bit to buy. They are around $25/27 here in Canada at the Borg. I found them for $12-14 in Lowes over the border in Port Huron MI.
You also need a battery and switch in order to open the electric valve. You can make that yourself with a pair of 9v batteries in series with a momentary switch of some kind. I macgyvered this instead. I had a flashlight that came with my 12v hitachi drill/driver kit. The flashlight died ages ago, so I ripped off the top and wired it up with some lamp cord to the valve. That gave me a quick, safe, and easy way to hook up a 12v battery (since i just pop it in and out of the bottom) and a switch all in one. Now one issue is that this is an on/off switch, and not a momentary switch. So we have to remember to hit the switch twice each time, so that it also turns off and releases the valve. (and as a matter of extra safety we are always pulling the batter out of the handle any time we stop using it. I don't want any power in the system when it is not being used.)
Here it is, ready to launch. I found it impossible to catch it mid-way through a launch with my camera. I might try again tomorrow.
Here it is, way up top in the photo, falling fast. It is about 1/3 of the way down at this point.
I repeat, there is no parachute, the rockets just fall "lightly" to the ground. I still would recommend you NOT be standing under it as it falls!