| Rewind Button: The Rewind button is only accessible during Stop mode and Pause mode. Clicking on Rewind rewinds the simulation either back to the start time (0.0 seconds on the clock) or back to last paused time. You can rewind as many times as you paused in the current simulation run (if rewinding in Pause mode), or one more than the number of pauses in the last simulation run (if rewinding in Stop mode). If you never pause during a simulation run, clicking on rewind undoes all the changes wrought by the simulator during the last simulation run. Keep in mind the fact that Rewind only undoes the automated simulations of body dynamics. It does not undo any changes YOU make as the user. For example, suppose that before a simulation run, you selected a thruster (which must be attached to a body). Then, during the simulation, you rotate the thruster so that the body experiences impulsive forces from several different directions. If you pause and then click on Rewind, the body will lose any velocity gains and return to its pre-run position. But the thruster's rotation angle stays unchanged. Because you, not the simulator, rotated the thruster, the Rewind button could not undo the rotation.