Status of Japan's Mars Explorer "NOZOMI"
Some of you might have read a report of a newspaper; "NOZOMI, Japanese made Mars exploration probe is to collide with Mars”.
But this description is not correct. The truth is that “NOZOMI” will, if going as it is, approach Mars on December 14 by 894km passing above Martian surface at its closest approach, but there would not be excluded a theoretical possibility of colliding with Mars by more or less one percent, if we take the error of orbit determination into account.
The international organization called “COSPAR” representing worldwide space science organs defines “Planetary Protection Policy” as special protective measure that provides for regulating a percentage possibility below one percent of falling upon Mars, within twenty years after the launch, for Mars orbiting satellites inadequately sterilized. On the other hand, from the standpoint of observing Mars, it is naturally better to get closer to Mars as much as possible, which means, therefore, the closest distance of 894km is marginally and most appropriately set for probe trajectory to take.
As you may know, however, “NOZOMI” right now is under “the last challenge” to repair its malfunction of which must be concentrated by all task force of scientists and engineers of “NOZOMI” mission team until its outcome is clearly known. Upon recovering from the damage, we will then work on putting the probe to orbit around Mars and resume its exploration. Unfortunately, if not restored, we will try to adjust the closest approach as far as possible from 894km. In this case, “NOZOMI” will, after once approaching Mars, escape from Martian gravitational sphere to become an artificial planet going around the orbit of the sun forever. As many of you may know, onboard “NOZOMI” is mounted an aluminum plate etched with the names of 270,000 people who applied for the pre-launch campaign, “Send your names to Mars!” The names of 270,000 people will keep on circling around the sun for hundreds of million years.
As long as “NOZOMI” team is at work, please give us a little more time until around Dec.10. When final result is known, we are ready to explain everything plainly to you and offer our sincere feeling and thinking.
We believe what the mission team can do is not to give up but to do the best until the very last moment toward responding the expectation of the people including those who kindly left their desires to this spacecraft.
November 20, 2003