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After numerous tries, the private effort to put ISEE-3 back into its original orbit has failed.
We have completely accomplished all of our original goals except for one: firing the ISEE-3 propulsion system in a sufficient fashion to alter its trajectory. We did operate the propulsion system briefly so as to correct the spin of the spacecraft, and to start the trajectory correction maneuver. The propulsion system works fine. The problem is that there is no longer any Nitrogen pressurant left in its tanks to allow it to work.
36 years and more than 30 billion miles have taken its toll on the spacecraft’s propulsion system. We have exhausted every option to bring the engines online so as to conduct the correction maneuver required to place it in its planned orbit. Without the pressurant it just won’t work.
Have they given up? No! Though the spacecraft will remain in a solar orbit where maintaining communications will be difficult if not impossible, they are going to try anyway, and are even going to run another crowd-sourcing campaign to finance it.