To make sure this rocket makes it safely into Earth's orbit, SpaceX and NASA will need a bit of luck when it comes to Mother Nature.
The 45th Space Wing, an arm of the US military, is constantly monitoring the weather — both at the launch pad and across a broad stretch of the Atlantic Ocean.
The team uses all sorts of instruments, including radars and weather balloons, to ensure that the rocket will have a smooth ride all the way through the upper atmosphere. And conditions are monitored at sea as well: If the rocket misfires and SpaceX's Crew Dragon capsule needs to use its emergency abort system to jettison the astronauts to safety, they'll land in the ocean. And that means officials must ensure that landing won't be made more dangerous by a severe storm or rough waves, so they scan a massive stretch of the Atlantic Ocean all the way to the coast of Ireland.
The 45th Space Wing's weather squadron keeps in constant contact with SpaceX officials, and together they make the final call on whether to move forward or hold off on launch.