Photos: Atlas 5 launches SBIRS GEO Flight 3

SpaceX test-fired a Falcon 9 rocket for the second time Saturday after replacing a valve following an earlier static fire test Wednesday. The move has postponed the Falcon 9 rocket’s launch with the Amos 17 commercial communications satellite to no earlier than Tuesday.

Following delivery to the launch pad, the United Launch Alliance Atlas 5 rocket stands poised for the NROL-61 mission for the National Reconnaissance Office from Cape Canaveral on Thursday morning.

The Delta 4 rocket to launch the next Global Positioning System satellite to sustain the orbiting navigation network has been rolled out to the launch pad.