Wife and i were out watching the international space station pass over our house. after it passed we were going inside. i saw another object moving out of the west at the same speed as the space station but it was 20 degrees north of the space station track. i said to my wife: look another satellite. it then suddenly accelerated to about 5x the original speed on what appeared to be a descending sw track, moving what would be approximately 2-3 thumb widths on an extended arm. it then stopped as suddenly and remained motionless for approximately 5 seconds. i recall saying to my wife, who was behind me : are you seeing what i'm seeing? she concurred. it then accelerated nw and appeared to be ascending and faded out the same way the space station does when it reaches the terminator. the time of the event can be ascertained by checking nasa's schedule for the space station that evening. i spotted the object less than 30 seconds after the space station disappeared over the horizon.Don't know if we were looking at a supply shuttle but the multiple trajectories seem to rule this out.