The Bottle Rocket on Steroids:
Rechargeable Rocket Launcher – up to 100 metres height. This would be a great project for an idle weekend: http://www.instructables.com/id/Rechargeable-Rocket-Launcher/
bottle rocket launcher
The Ultralight Hiker
Ultralight hiking, backpacking, bushwalking, deer hunting, canoeing, pack rafting, tips, trails, adventures, gear, reviews...Over 1600 posts & 70 years' experience.