One significant room for improvement over the existing Shuttle is the computer system used to navigate the orbiter and control its onboard systems. While there are five redundant computers on the shuttle for these tasks, they are 1970s technology, making their overall processing ability less than a modern graphing calculator. Today's advancements in computers, with processing ability doubling every year and a half, allows for computers to control much more of the spacecraft with better logic and analysis abilities, nearly automating the entire functions of the vehicle. Since the orbiter is designed to be a no-fuss, easy, and most importantly, reliable, vehicle to return to earth in the event of an emergency, computers will be used extensively on this orbiter.

    The X-38, using Global Positioning Satellites, navigated its parafoil and landed precisely on a target after being dropped from over 30,000 feet. This was completely unmanned, and was repeated several time at different altitudes and wind speeds to show how adaptable the software was to varying conditions without human intervention.  The capacities and added benefits of modern computing technology when coupled with GPS is discussed in more depth in the Guidance Subsystems Report.

    Only the International Space Station shows the ability of computer controlled vehicles.  The environment lends itself nicely to an automated environment, as so much of it is electrical and sensors are scattered throughout the ISS to monitor the performance of its various systems.  Unfortunately, the ISS does not take advantage of the available computing power to automate many tasks; many still require human intervention, making computers mere replacements for the hundreds of toggle switches typically associated with spacecraft.  Computers are capable of automating many tasks using logic algorithms, allowing the astronauts to focus their efforts elsewhere.

    Computers play an important role in the safety of the vehicle.  As sensors improve in both quality and quantity, the computers can be fed more information to assess the performance and health of the various systems.  This potential of this technology demands its own computer system, designated the Vehicle Health and Management (VHM) by the X-33 program.  If performance is unexpected or a system is failing, the VHM computer can recommend a the Command and Control (C&C) computer to switch to a redundant system.  If the pending failure would be catastrophic, VHM can request that C&C shut down the system before it becomes a hazard.   

    All the while the guidance subsystem is not only keeping the vehicle precisely on its optimal trajectory, but also calculating numerous trajectories to take in the event of an emergency.  Once C&C switches to abort mode, guidance sends back the possible abort trajectories available at that moment in time.  C&C decides on the best trajectory given its mission objectives, and instructs guidance to switch to the designated trajectory.  All of this would take place milliseconds, before the crew is even aware that a problem exists.

    The data gathered by the VHM provides more than real-time decision making on the safety of the vehicle, but also provides performance data on the individual systems.  This data is invaluable on the ground, showing what needs maintenance before the next flight and what is running smoothly.  This significantly reduces the amount of time required for checking and diagnosing each individual subsystem searching for problems.

    Each crew member is has a large flat screen monitor with touch screen, essentially a custom built performance laptop.  Since these computers are connected directly to the vehicle's internal communications network, any information the astronaut desires is available in real time from any system.  This direct connection into the network also provides redunancy in the event that a specific computer fails, taking the roles of the failed computer instantly.  This network also provides processor-load balancing, so that if an individual computer is receiving more data than it can process another computer can take up the slack.

    Manual control is also provided via these general purpose computers, removing the toggle switches and providing much more intuitive and easier interfaces.  These allow for faster response times and virtually eliminates hitting 'the wrong switch,' which has resulted in some close calls over the years.

    This sophisticated network of specialized and general purpose computer provide the safest and most versatile spacecraft designed, being able to react to any suituation at a moment's notice.