With modern space travel now the work of private industry operating under the guidance of NASA, how do you make sure that the custom hardware running on, say the Dragon Module interfaces with the custom hardware aboard the ISS? You bug-test the shit out of them beforehand in NASA's Systems Engineering Simulator.
Located at the Johnson Space Center in Houston, TX, the Systems Engineering Simulator (SES) is a staging ground to test space-bound vehicles, systems, and personnel before they leave the atmosphere. Well, to be fair, it's actually a trio of simulators, each specializing in the testing of specific cockpit designs. Each dome does allow for a wide range of tests—docking contact dynamics, vehicle control systems, robotic manipulator dynamics, and measurement of thruster plume impingement. It also accounts for a bevy of environmental factors, including gravity gradients and solar and lunar ephemerides.
All of this allows researchers, both from NASA and the likes of Space X or Virgin Galactic, to rigorously run virtual tests of concepts for tomorrow's orbiters—typically at a significant savings compared to repeated test flights employing small-scale mock ups. It also provides astronauts-in-training a highly accurate reproduction of what they're likely to encounter on mission, allowing them to practice approaches, robotic grappling, docking, and descents until they're perfect.
Each simulator is a dome (the Alpha and Beta models both have a 24-foot diameter, while the Mini dome is 21-feet wide) into which a cockpit mockup is inserted. Depending on which dome is employed, the SES recreates the interior of every active space vehicle—the HTV, Dragon, Cygnus, Orion, SEV—hell, you can even pretend to command the ISS itself.
Each dome employs a number of HD projectors to paint orbital scenes on the dome's interior. Alpha Dome, for example, uses eight 1600x1200 projectors, while Beta uses 11 projectors at 1400x1500, and Mini uses eight 1400x1500's. All three have Dolby 5.1 surround sound systems as well. Because it has to look and sound real, too.