Replacement Vulcan test launch with inert payload, experiments, and demonstrations for certification with the USSF after delays caused by payload testing of the Sierra Space Dreamchaser CRS SNC-1 mission, the original planned payload. One of the GEM-63XL SRBs was observed to blown out its booster nozzle at T+37 seconds, causing reduced and asymmetric thrust during ascent, however the performance shortfall was fully compensated by Vulcan's other stages.

Vulcan Centaur is a two-stage-to-orbit, heavy-lift launch vehicle under development by United Launch Alliance (ULA) since 2014. It is principally designed to meet launch demands for the U.S. government's National Security Space Launch (NSSL) program for use by the United States Space Force and U.S. intelligence agencies for national security satellite launches. It will replace both of ULA's existing launchers (Atlas V and Delta IV Heavy) in this role, as these launchers are retiring.

United Launch Alliance (ULA) is a joint venture of Lockheed Martin Space Systems and Boeing Defense, Space & Security. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. ULA launches from both coasts of the US. They launch their Atlas V vehicle from LC-41 in Cape Canaveral and LC-3E at Vandeberg. Their Delta IV launches from LC-37 at Cape Canaveral and LC-6 at Vandenberg.

• United Launch AllianceCommercial