FIRST team 1351 tests its spring catapult for the 2008 game, which will be used to launch trackballs ~8ft into the air. Toward the left side of the video the PVC pole used to measure can be seen (barely, its on the left of the big white column). There are black tape markings every 1 foot, starting 3 feet off the ground. The ball goes roughly 6.5 feet in the air, when measured from the ground (about 2.5 tape markings from the top of the pole).