ULA Launches USSF-8 with only Atlas V 511

Credit: United Launch Alliance

On Friday, January 21 at 2pm ET (19:00 UTC), ULA (United Launch Alliance), a joint venture between Boeing and Lockheed Martin, launched the USSF-8 mission for the United States Air Force atop an Atlas V 511 rocket from SLC-41 at the Cape Canaveral Space Force Station in Florida. The 45th Space Wing of the US Space Force predicted a 90% probability of favorable weather at the opening of the launch window. Atlas V 511 is a configuration of the Atlas V rocket. The "5" is the diameter of the payload fairing in meters, the first "1" is the number of solid rocket boosters, and the second "1" is the number of RL10 engines on the Centaur III (Common Centaur) upper stage. This was the first and only launch of the 511 configuration, nicknamed "Big Slider". Atlas V 511 is a very unique rocket, because it only has one solid rocket booster instead of multiple or none. Many people ask how a seemingly assimetric rocket can fly correctly. It can do this becuase first of all the solid rocket booster's nozzle doesn't move (s0 it is aligned with the rocket's center of gravity) and second because the first stage engines can gimbal so the rocket stays on its course. The USSF-8 mission has two satellites, GSSAP-5 and 6. These satellites are designed by the United States Space Force to test more accurate tracking and classification of human-made objects in orbit. They will be placed directly in geo-stationary orbit by the Centaur upper stage. This was the 6th orbital launch attempt of 2022, 148th United Launch Alliance mission and the 91st Atlas V launch.