Space X set to launch on Saturday May 19

The private company Space X is set to launch its Falcon 9 rocket with the Dragon space capsule to the International Space Station on Saturday, May 19, with a backup launch date of May 22. The launch is set for 04:55 a.m. Eastern time, which is 09:55 08:55 UTC -- there'll be a live webcast at Space X's site and no doubt NASA TV will carry it as well. They have what's called an "instantaneous launch window", which means if they don't launch right on time they can't just wait a few minutes and try again; they'll have to go to their backup date. The reason for this is the vagaries of orbital dynamics. The space station is circling the Earth, the planet is rotating underneath it, and the rocket itself has a certain amount of thrust to get Dragon into orbit so it can catch up to ISS. All this adds up to a single Go/No Go decision at the appointed time.