The first stage in a NASA mission to send astronauts back to the Moon is due for take-off today.
The flight will be unmanned, but it's seen as another step closer to one day sending people back.
The rocket will be launched from Florida and will stay in the air for 42-days.
The NASA launch mission will be led by a woman.
When Neil Armstrong became the first person to step foot on the moon in 1969, there was only one female among hundreds of officials and engineers.
It's hoped a manned mission to the moon will depart in 2025.
