Tech Know: The weekend rocket inventors' club
14 July 2010 Last updated at 05:40 BST
Ellie Gibson meets the inventors who fire four-metre long rockets into the skies above Cambridgeshire.
The East Anglian Rocketry Society (EARS) spends weekends camping alongside a corn field while launching rockets hundreds of metres above the ground.
Video from the air supplied by Andy Hugh and Pete Davy