"During our session with Arecibo today we came very, very close to firing the thrusters on ISEE-3 for its spin-up maneuver. But we were not able to complete the process and fire the thrusters. The spacecraft was completely configured for a thruster firing during today's pass. We reduced the number of pulses from 11 to 1 to make certain that we had the proper commands in place. If that engine firing proceeded successfully we'd follow with the remaining 10 pulses so as to spin up the spacecraft to the required rotation rate. As it happened we were unable to get confirmation on the very last command and put a halt to the procedure."
Keith's note: We have another window opening at Arecibo around 1:30 pm EDT. We'll be live tweeting at @ISEE3Reboot.
Keith's Update: Our Arecibo pass was a short one and we had some commanding issues - so no spin-up burn. Our DSN pass for ranging starts at 4:50 pm EDT - you can see ISEE-3 listed on the DSN live page.