Screen Shot (click on image for larger view) Purpose of the Simulation: To provide the public with an interactive simulation to experience the challenges of spacecraft docking The space shuttle docking simulation, showcased at the San Jose Tech Museum of Innovation's 2001: Destination Space exhibit section, was developed by the Smart Systems Research Lab, located at NASA Ames Research Center at Moffett Field, CA. This simulation is a simplified version of the rendezvous and docking scenario performed by astronauts when docking the Space Shuttle to the International Space Station (ISS). When the Shuttle docks with the ISS, the operation takes several hours and requires precise accuracy. An astronaut works in six degrees-of-freedom environment (which means he/she has to worry about the x-translation, y-translation, z-translation, pitch-rotation, yaw-rotation, and roll-rotation). The astronaut uses two separate joysticks to handle all six degrees-of-freedom. In this particular simulation, the operating scenario has been reduced to three degrees-of-freedom (x-translation, z-translation, and roll-rotation) with one joystick. There are also orbital mechanic effects in space that make maneuvers more difficult (briefly, orbital mechanic effects cause maneuvers to have a slight arc because the earth's gravity pulls objects back towards it). Again, to simplify matters, the orbital mechanic effects have been neglected in this simulation (when you push the joystick forward, in the +z direction, the shuttle will just translate forward in the +z direction). Note however that space is a frictionless environment. If the joystick is pushed in any direction, even for just a brief second, the shuttle will keep going in that direction unless the joystick is pushed back in the opposite direction to counteract the thrust that had been initiated. Flying the shuttle in space is very different from driving a car or flying a plane. There is no friction to slow the shuttle down. SSRL is using a more complicated form of this simulator (i.e. full six degrees-of-freedom, integrating orbital mechanics effects, etc.) to test out various control and optimization techniques to validate and simulate various scenarios (it would be impractical and highly unsafe to perform these tests on the actual shuttle with astronauts onboard). The Smart Systems Research Lab (SSRL) conducts cutting-edge research on various projects that require utilization of advanced soft computing techniques to achieve “smart” operation resulting in improved performance. One of these projects deals with Spacecraft Docking. The objective of this research is to increase safety, accuracy, and efficiency of spacecraft docking. SSRL is developing computer-aided joystick control using adaptive neurocontrol technologies that can learn in near real-time change in spacecraft mass properties, degradation in thruster strengths, and effects of uncontrolled venting (e.g. uncontrolled gas venting on Apollo 13 resulting from an onboard explosion). Thus, if thruster strengths or the mass properties of the spacecraft change, an adaptive control system is able to “adapt” and compensate for the variation and assists the astronaut. The technology developed could make spacecraft docking safer, more accurate, faster, and more fuel efficient.
San Jose Tech Museum Docking Simulation