After our first attempt to do DSN ranging yesterday we discovered that we need to put ISEE-3 into coherent ranging mode and then promptly issue commands. If we wait too long the spacecraft will drop out of coherent ranging mode. We've been suspecting that this has been an issue before. So, we are working with DSN to resolve this issue in advance of our next ranging attempt. As such, our Sunday DSN pass has been cancelled. The next opportunity will be on Wednesday from Canberra, Australia. Further information can be found at "ISEE-3 Reboot Project Scheduled for DSN Doppler and Ranging Activity".
In the mean time, due to some pulsar observations that need to be conducted at Arecibo, we have moved up our ISEE-3 Spin-up burn to tomorrow, Friday 20 June. Our window at Arecibo opens around 1:18 pm EDT. We'll be performing the burn during the following several hours. For more information on this burn and the ISEE-3 pripulsion system check out these links.