Photos: Gantry retracted from Atlas 5

United Launch Alliance, the incumbent leader in U.S. rocketry, goes for its 100th flight Friday, a milestone nine years in the making after eclectic missions to Mars, the moon and Jupiter, and deployments of commercial, military and reconnaissance spacecraft.

A United Launch Alliance Atlas 5 rocket will boost NASA’s Tracking and Data Relay Satellite-M, or TDRS-M, into space from Cape Canaveral on Aug. 18 at 8:03 a.m. EDT (1203 GMT).

Rocketing through gloomy skies with a payload clouded in a veil of secrecy, a United Launch Alliance Atlas 5 rocket fired away from Cape Canaveral on Tuesday to deploy a satellite thousands of miles above Earth.