Marco Caceres, an analyst with the Teal Group, says there is a strong business case for ULA to retire the Delta IV, as the cost for keeping two redundant lines is significant. But he also acknowledged that there is a smart political angle at work. "If they were to cancel the Delta IV medium and all they have is the Atlas V, then there is a better argument to be made for preserving the RD-180 shipments," Caceres said. "No question about that. Have they thought about it? I'm sure people at ULA have considered it as a good strategic move."

But, Caceres said, there are many practical reasons for ULA to move away from the Delta IV, a largely redundant and expensive capacity. He notes that part of the reason Bruno was brought in to lead ULA last summer was to streamline the company in the face of SpaceX's competition. "If the Air Force wants ULA to be more competitive on price, it has to become leaner, and it can't do that with two redundant systems," Caceres said.

"Overall, I would rate it as a success," Marco Caceres, director of space studies with Teal Group, a Fairfax, Virginia-based consulting firm, said in a phone interview.

"It is tricky to hit something that small to begin with, but to hit with the right velocity so that it lands perfectly when the barge is moving in the ocean -- that's a tough challenge," Caceres said. "They're not taking the easy way. That's not the conservative approach."