The National Aeronautics and Space Administration (NASA) is developing plans for the successor to the Space Shuttle. The Constellation Program within NASA is responsible for developing the Crew Exploration Vehicle (CEV) and related systems to provide astronauts with access to space. The CEV will include many improvements over previous spacecraft, and numerous NASA groups are involved in designing those improvements. For example, the Space Human Factors Engineering (SHFE) project is supporting work on a range of tasks including crew training, cockpit displays, and crew anthropometry. Additional improvements will focus on launch and landing site operations. Within the CEV itself, an upgraded caution and warning system will increase the crew's abilities to diagnose and resolve malfunctions. CEV ergonomics are critical since the vehicle will support several configurations of crew and cargo to maximize its operational flexibility. Work on CEV habitability is being based on numerous factors such as a task analysis to identify critical crew activities. All of these tasks will help ensure that the next-generation spacecraft provides safe and efficient access to space.