A United Launch Alliance Vulcan rocket is gearing up to carry a classified national security payload into space Tuesday night for the United States Space Force.

In the near-term, ULA will switch back to launching its soon-to-retire Atlas V rocket, the Vulcan rocket's predecessor. The company has 13 more Atlas Vs in its inventory, most of them sold to Amazon and Boeing to launch Kuiper Internet satellites and Starliner crew missions to the International Space Station.