Falcon 9 rocket for the first time, carrying a Dragon spacecraft prototype. In theory, the new ship will haul cargo and crews of seven astronauts to the ISS.
Update: Launch has been aborted at the last second. No news on what happened, but they still have time to restart the countdown before the launch window ends at 3pm EDT.
Update 2: Launch process has restarted. Stay tuned.
Update 3: It launched. Video added to the post.