Deep Impact eliminating five: how to ensure the accuracy of impactor hit the comet nucleus.

<P> How to ensure the accuracy of impactor hit the comet nucleus </ P> <P> impactor carried with 25 m / s advance speed of the hydrazine propulsion system to promote the necessary amendments to the orbit and attitude control. .Navigation system uses hydrazine thrusters to control the flight path change at 1 mm / s within the accuracy. .In addition, in "Deep Space One," the automatic detector tested navigation software is also "help" impactor accurately performed tasks. ."Deep Impact" probe experts believe that the chance of missed targets is less than 1%. .</ P> </ p>.