Operational considerations and comparisons of the Saturn, Space Shuttle and Ares launch vehicles

The United States (U.S.) space exploration policy has directed the National Aeronautics and Space Administration (NASA) to retire the Space Shuttle and to replace it with a new generation of space transportation systems for crew and cargo travel to the International Space Station, the Moon, Mars, and beyond. As part of the Constellation Program, engineers at NASA´s Marshall Space Flight Center in Huntsville, Alabama are working to design and build the Ares I, the first of two large launch vehicles to return humans to the Moon. A deliberate effort is being made to ensure a high level of operability in order to significantly increase safety and availability as well as reduce recurring costs of this new launch vehicle. It is the Ares Project´s goal to instill operability as part of the requirements development, design and operations of the vehicle. This paper will identify important factors in launch vehicle design that affect the operability and availability of the system. Similarities and differences in operational constraints will also be compared between the Saturn V, Space Shuttle and current Ares I design. Finally, potential improvements in operations and operability for large launch vehicles will be addressed. From the examples presented, the paper will discuss potential improvements for operability for future launch vehicles.