Autonomous space shuttle

The continued assembly and operation of the International Space Station (ISS) is the cornerstone within NASA's overall Strategic Plan. As indicated in NASA's Integrated Space Transportation Plan (ISTP), the International Space Station requires Shuttle to fly through at least the middle of the next decade to complete assembly of the Station, provide crew transport, and to provide heavy lift up and down mass capability. The ISTP reflects a tight coupling among the Station, Shuttle, and other programs to support our Nation's space goals. While the Shuttle is a critical component of this ISTP, there is a new emphasis for the need to achieve greater efficiency and safety in transporting crews to and from the Space Station. This need is being addressed through the Orbital Space Plane (OSP) Program, recently redefined as the Crew Exploration Vehicle (CEV). However, the OSP/CEV is being designed to "complement" the Shuttle as the primary means for crew transfer, and will not replace all the Shuttle's capabilities. The unique heavy lift capabilities of the Space Shuttle is essential for both ISS, as well as other potential missions extending beyond low Earth orbit. One concept under discussion to better fulfill this role of a heavy lift carrier, is the transformation of the Shuttle to an "un-piloted" autonomous system. This concept would eliminate the loss of crew risk, while providing a substantial increase in payload to orbit capability. Using the guidelines reflected in the NASA ISTP, the autonomous Shuttle a simplified concept of operations can be described as; "a re-supply of cargo to the ISS through the use of an un-piloted Shuttle vehicle from launch through landing". Although this is the primary mission profile, the other major consideration in developing an autonomous Shuttle is maintaining a crew transportation capability to ISS as an assured human access to space capability. Although the current Shuttle has the capability in numerous areas to operate without crew interaction, there are still many tasks that can only be accomplished through a direct action by a crewmember. In addition to the standard or nominal crew actions required during a Shuttle mission, the availability of the crew to detect or react to off-nominal or contingency situations is an essential function that would be very difficult to replace. The primary set of changes required to move to an autonomous Shuttle are those associated with the replacement of the standard or "nominal" crew operations. This replacement can be accomplished either through onboard automation or creating the ability for ground or ISS commandable operations. In addition, the challenges and issues associated with retaining situational awareness and dealing with failures or contingencies are much more complex and difficult to resolve. When addressing the transformation to an un-piloted. Shuttle system, numerous hardware, software and procedural changes will be required to both flight and ground systems. An important consideration in the incorporation of these changes is the need to perform-these modifications as a "block" update to the Shuttle system, to minimize the impacts and complexities associated with the operations of a mixed fleet. Converting the Shuttle fleet to an autonomous system will be challenging and expensive. Although an autonomous Shuttle eliminates the risk for loss of crew, the risk to mission success could potentially be increased. Previous Shuttle experience in space has demonstrated that the human presence provides an invaluable capability to successfully react to any situation that may arise. This capability cannot be easily "automated" or replaced.