This is an image of an Atlas V being lifted into position on 31 January 2018. Photo credit: NASA/Ben Smegelsky.
Since then the rocket has been topped with a new American weather satellite called the GOES-S and will be watching the weather in the western US. The GOES-S is another in a series, the GOES-R became the GOES-16 and watches the eastern US the GOES-S will become GOES-17. There will be two more in this series the GOES-T and U.
The launch day has arrived and at 17:02 EST / 22:02 UTC a two-hour launch window will open, during which GOES-S will launch on a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station (CCAFS) in Florida.
Launch coverage will begin shortly after 20:30 UTC / 16:30 EST.