A new generation of spacecraft is now under development by NASA to replace the Space Shuttle and return astronauts to the Moon. These spacecraft will have a manual control capability for several mission tasks, and the ease and precision with which pilots can execute these tasks will have an important effect on mission risk and training costs. This paper focuses on the handling qualities of a spacecraft based on dynamics similar to that of the Crew Exploration Vehicle, during the last segment of the docking task with a space station in low Earth orbit. A previous study established that handling qualities for this task degrade significantly as the level of translation-into-rotation coupling increases. The goal of this study is to evaluate the efficacy of various pilot aids designed to mitigate the handling qualities degradation caused by this coupling. Four pilot tools were evaluated: dead-band box/indicator, flight-path marker, translation guidance cues, and feed-forward control. Each of these pilot tools improved handling qualities, generally with greater improvements resulting from using these tools in combination. A key result of this study is that feedforward control effectively counteracts coupling effects, providing solid Level 1 handling qualities for the spacecraft configuration evaluated.
A piloted simulation studied the handling qualities for a precision lunar landing task from final approach to touchdown. A core model of NASA's Altair Lunar Lander was used to explore the design space around the nominal vehicle configuration; details of the control and propulsion systems not available for that vehicle were derived from Apollo Lunar Module data. The experiment was conducted on a large motion base simulator. Eleven Space Shuttle and Apollo pilot astronauts and one test pilot served as evaluation pilots, providing Cooper-Harper ratings, Task Load Index ratings, Bedford workload ratings and qualitative comments. Following attitude guidance cues, the pilots evaluated control powers ranging from 1.1 to 4.3 deg/s 2 , maximum rate commands from 3 to 20 deg/s, which is equivalent to a range of inceptor sensitivities, and two magnitudes of disturbance moment arising from propellant slosh. The handling qualities were satisfactory for the highest control powers and low inceptor sensitivities, with reduced sensitivity both improving handling qualities and reducing propellant use for a given control power. Pilots used low attitude rates regardless of the maximum rate available or control power. Propellant slosh degraded handling qualities approximately one Cooper-Harper Rating.
Autonomous UAV science missions hold great promise for improving the productivity of airborne science research and applications. Potential UAV science missions have been reviewed and common autonomy needs have been identified. Preliminary efforts to craft an Intelligent Mission Management architecture for observational autonomy are evolving. Three science missions, along with the architecture, the technology needs and operational requirements for autonomy are highlighted.
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