During the post-tanking cleanup and systems testing of the GLV, spacecraft No. 10 hypergolics were serviced (June 27-28), spacecraft Final Systems Tests were conducted (June 28-July 1), crew stowage was evaluated, and the extravehicular life support system was checked (July 1).

On July 5, spacecraft and GLV were mechanically mated and the erector was cycled. The electrical interface was retested July 6. The Simultaneous Launch Demonstration on July 12 and Simulated Flight Test on July 13 completed prelaunch testing.