SpaceX says it completed a test-firing of a Falcon 9 rocket at Cape Canaveral Air Force Station on Wednesday in preparation for liftoff this weekend.
A four-hour launch window opens this Saturday at 11:28 p.m. Eastern time.
The mission payload is the Telstar 18 Vantage communications satellite, serving China, Mongolia, Southeast Asia, and the Pacific Ocean region, and sister to the Telstar 19 launched in July.
Air Force forecasters predict a 60-percent chance of favorable weather conditions, with possible cloud cover being the main concern.