"Boeing's cost structure is higher than SpaceX — that's just a fact," said Marco Caceres, senior space analyst at the Teal Group.

Because the aerospace giant has been around longer, it most likely has an older, more experienced workforce with higher wages and labor costs, he added.

But the biggest cost differences likely come from manufacturing processes. Boeing builds its Delta rocket and Atlas V launchers in a vertical position, while SpaceX's Falcon 9 rockets are assembled horizontally, which is easier and saves on time.

Meantime, SpaceX is a vertically integrated company, building all of its parts in-house, with no subcontractors. Boeing employs numerous subcontractors to build components, which adds to costs. "When you become a more established company, you can't be a specialist in everything," Caceres said.

Shifting 777X work to St. Louis will help Boeing reinforce its industrial and political presence in an area hit hard by the downturn in U.S. military spending, said Richard Aboulafia, analyst with the Virginia-based Teal Group.

He said the decision also reflected Boeing's desire to build more commercial parts in-house after it ran into quality and schedule problems with 787 parts made by outside suppliers. "This will reduce risk on commercial jet programs," he said.

"Boeing is at a disadvantage in terms of next generation narrow body timing because Airbus is doing a great job with the A320neo," said Richard Aboulafia, aerospace consultant for Teal Group.

First delivery of the A320neo is scheduled for the fourth quarter of 2015 to Qatar, while first delivery of the 737MAX is scheduled for the third quarter of 2017 to Southwest (LUV) .

"Airbus is going to get there the better part of two years earlier than Boeing," Aboulafia said. "The best thing Boeing can do is to catch up with them as soon as possible. In this high-fuel-cost environment, it's a game of availability; it's all about timing."

"SpaceX is the new kid on the block, but it's proven its capabilities very quickly," said Marco Caceres, director of space studies with Teal Group, a Fairfax, Virginia-based consultant. "SpaceX would love to be the first commercial company to land its own private astronauts on the moon and eventually go on to Mars."

"It's entirely possible that we wake up one day and the Russians say, 'We're not taking your astronauts up anymore,'" said Marco Caceres, director of space studies at Fairfax, Virginia-based consultant Teal Group. "NASA's anticipating this possibility. That's why they want to move as quickly as possible with this program."