The company launched a rocket from Vandenberg Air Force Base, California, in January with success.
At the time, SpaceX officials said they took corrective action on all possible causes of the September explosion.
The rocket was packed with cargo Friday that will be brought to the International Space Station. The cargo will contain 5,500 pounds of science experiments, research equipment and supplies for astronauts.
It's standing on launch pad 39A, with a Dragon supply ship on top.
Astronauts lifted off from pad 39A six times from 1969 to 1972 on their way to the moon. The pad hasn't been used since the retirement of the space shuttle program.