United Launch Alliance

Perseverance's launch has been delayed by two days to July 22. The announcement came after engineers found issues with ground support equipment but both the spacecraft and vehicle "remain healthy."
In an official statement, the agency wrote: "NASA and United Launch Alliance are now targeting Wednesday, July 22, for launch of the Mars 2020 mission due to a processing delay encountered during encapsulation activities of the spacecraft. Additional time was needed to resolve a contamination concern in the ground support lines in NASA’s Payload Hazardous Servicing Facility (PHSF)."