At 7:21 pm EST, the lift off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, was called off with the order to shutdown the engines of the Falcon 9 rocket at the moment of ignition. Today's launch would have been SpaceX's most ambitious to date, as it was to be the first attempt at a powered landing of the Falcon 9 on a sea barge after returning from a geostationary transfer orbit launch.

No cause has yet been determined for the abort, though mission control did indicate that telemetry readings showed some form of malfunction just as the ignition sequence started. This was the final second during which a pre-launch abort could be made. It was hoped that a final attempt might be made this evening, but this was abandoned as the flight crew required more time to assess the situation.

Today's abort came after a series of delays of the SES-9 mission. Two previous launch aborts on Wednesday and Thursday last week were due to problems with the supercooled liquid oxygen, followed by a range safety issue on Sunday that triggered a last-minute hold.