As many of you have probably read, the ISEE-3 Reboot Project was able to successfully send uplink commands to the space craft. This was accomplished through a lot of team work, strong leadership by Dennis Wingo, and generous support from the community at large. Balint Seeber and I were fortunate enough to work on the communications for this project. When you tell most people that you designed a deep-space uplink modulator in a couple of days, there is a good chance that they will be fairly impressed.
"Communicating with a space probe using SDR: The @ISEE3Reboot Project" , presentation by Balint Seeber, Ettus Research (PDF)