Our next window at Arecibo is tomorrow (Wednesday) between 12:19 pm and 3:03 pm ET. During that opportunity we intend to attempt a deep space plumbing repair on board ISEE-3 and then fire its engines.
Right now we still only need approximately 10 m/sec of Delta V for the Trajectory Correction Maneuver (TCM) so we're looking good in terms of fuel reserves. Based on the number of thruster firings we achieve during that plumbing repair session we'll need to do some additional firings - possibly over the course of several days - all of which will constitute the TCM.
If you have ever had to clean our your car's carburetor and fuel lines then you have an idea of what we will be attempting. More details to follow.