Live coverage: Delta 2 launches

The U.S. military’s next GPS navigation satellite was ready for launch from Cape Canaveral at 9:43 p.m. EDT Friday (0143 GMT Saturday) aboard a SpaceX Falcon 9 rocket. But SpaceX aborted the countdown just two seconds prior to liftoff.

Eight of Iridium’s first ten upgraded communications satellites launched in January started providing voice and data relay service ahead of schedule, and SpaceX says it can launch up to 40 more Iridium spacecraft by the end of the year, Iridium officials reported Thursday.

NOAA’s new JPSS 1 weather satellite deployed from its Delta 2 launcher in an orbit more than 500 miles above Earth nearly one hour after blasting off from California.