The Falcon 9 rocket had an abort at launch today at 5:39 Eastern.
The rocket is safe on the launchpad. They are assessing the situation. SpaceX has a remarkably good record of launching quickly and successfully after a launch abort, sometimes within an hour.
The countdown has been reset for a 6:44 pm Eastern launch, the latest they can in their launch window, and has resumed. You can watch it live here.
It appears that they have resumed the countdown, even as they continue to assess, so that if all is well they will be able to launch within their window. This means however they are not yet go for launch.
They now say they are go for launch, even as they assess. In addition, their customer, SES, has given them 20 more minutes on their launch window.
I just love how SpaceX seems to always have an abort-at-launch whenever I am free to watch. I think this is the fourth abort-at-launch nail-biter I have seen.
They have aborted the countdown again at T-48 seconds. They have also scrubbed for the day. It appears they had not completed their assessment of the original abort and decided to scrub. The next launch attempt date is not yet known.