Replanning of Rendezvous Docking Experiment of ETS-VII, and its Result.

ETS-VII is a test satellite to perform in-orbit demonstration of rendezvous docking (RVD) technology, which will be necessary for advanced space activities in the early 21st century. ETS-VII successfully performed autonomous RVD in the first experiment flight. But in the second experiment flight, seberal times of Z-thruster misfiring occurred and they prevented for ETS-VII to accomplish docking for three weeks. To verify all technical items, the third experiment flight was replanned on condition that firing Z-thrusters should be minimized. And we modified on-board software to continue approach in case that Z-thrusters misfiring occur. ETS-VII succeeded in the third experiment as the result of these countermeasures. We present replanning of the third experiment flight and its result in this paper.