According to MSNBC.com, SpaceX has been forced to delay the maiden launch of their Falcon 1 space rocket by 24 hours:

An upstart rocket company says it has delayed the startup of its launch schedule by at least 24 hours, due to the U.S. Army's need to prepare for a missile defense launch.

The maiden launch for the Space Exploration Technologies Corp., or SpaceX, had been scheduled for 4 p.m. ET Friday from an equatorial launch site on an island in the Pacific Ocean's Kwajalein Atoll.

However, the El Segundo, Calif.-based company said in a statement issued late Thursday that the Army Space and Missile Defense Command had bumped the first launch of SpaceX's Falcon1 rocket by 24 hours, to 4 p.m. ET Saturday, "in order to facilitate preparations for a missile defense launch."