As NASA's next generation spacecraft matures, engineers will document its design with today's electronic equivalent to the blueprint. But diagrams, three-dimensional or not, only go so far in helping engineers understand what layouts best suit the job at hand and the humans involved.

Image to right: A mockup of NASA's new spacecraft comes together. Credit: NASA

That's why Johnson Space Center in Houston has started building a full-sized mockup of the new craft's cockpit in its Space Vehicle Mockup Facility.

The new spaceship -- known as the Crew Exploration Vehicle -- is the key to making NASA's Vision for Space Exploration a reality. A quick glance at the mockup reveals the resemblance to the original Apollo crew capsule. But the new capsule will be three times larger and is designed to carry four astronauts to and from the Moon, support up to six crewmembers on future missions to Mars and deliver crew and supplies to the International Space Station.

Inside, the mockup remains largely unfinished. A temporary floor foreshadows the location for launch and entry seating, and a large hatch dominates the top of the cone. The hatch is wide enough for a human to pass through easily and will be the point where the crew capsule will dock with a lunar lander for the first trip back to the Moon, currently targeted for 2018.

The mockup represents the first leg of a three-step design philosophy. In stage one, design teams discuss various theories over how best to utilize cockpit space and commit their ideas to paper. Then engineers use computer design programs to produce working 3-D models of the crew’s space. While work continues on these stages, team members simultaneously use the mockup to experiment with physical relationships in a real-world environment.

"You discover new things during each stage of the design process," said Jeff Fox, lead cockpit engineer on the spacecraft. "But your brain needs the input of physically standing inside the real volume of the interior space to get a true feeling of what should be the right layout."

Image to left: Workers attend to the details in building the mockup of NASA's new spacecraft concept. Credit: NASA

Workers are making changes to ensure the current model matches the inner measurements of the most recent design. Once that's finished, the team will start working on how to arrange seats and where to put the spacecraft's controls.

The team is already working on plans to arrange cockpit seating in three-, four- and six-person configurations. In the early phases, simple foam-core boxes will serve as substitutes for real-world hardware such as computers and cargo.

The stand-ins will gradually give way to more accurate versions of the real thing, helping the designers visualize what the computers can't show. As Fox puts it, "there’s just no substitute for reality."