SpaceX is now estimating a launch time of 7:30 PM Pacific Time for the launch of their Falcon 1 rocket.
Falcon 1 is a two stage, liquid oxygen and rocket grade kerosene (RP-1) powered launch vehicle. It is entirely privately funded. This will be the fifth launch of a Falcon 1. The first three launches failed to achieve orbit. The previous launch, their fourth, was their first successful launch to orbit.
Falcon 9, a larger version of this rocket, is a human-rated rocket designed to ferry the Dragon spaceship, which can carry up to seven people, to low earth orbit. SpaceX was granted a 1.6 billion dollar contract from NASA to ferry cargo to the International Space Station using a cargo version of the Dragon. The first launch of a Falcon 9 is scheduled for later this year.