Delta IV-Heavy launches on demo flight

12/21/04 ~ 4:50 p.m.

The largest rocket built since the days of Apollo and the Saturn family, the giant, 24-story Delta IV-Heavy rocket lifts off on its maiden flight. While only a partial success - the dummy payload onboard was left 10,000 miles short of geosynchronous orbit - the launch was declared a good demonstration. The cause of the failure was a premature shutdown of the first-stage engines, due to 'bubbles,' or air gaps tricking fuel sensors into thinking fuel had been depleted early.