So is it time to go back yet?
From the transcript at NASA:
188:01:27 Schmitt: Ten seconds.
188:01:28 Cernan: ...10 seconds.
188:01:29 LM Crew: Abort Stage.
188:01:30 Cernan: ...pushed. Engine Arm is Ascent.
188:01:32 Schmitt: Okay. I'm going to get the Pro. (Pause) 99 Proceeded 3, 2, 1...
188:01:39 Schmitt: Ignition.
[Schmitt - "As I recall, at the moment of ignition, all we had was static - loud static. And I was looking to see what happened, to see if I'd lost lock."]
[Cernan - "Jack spent half of the lift-off trying to get comm back."]
[Schmitt - "And I remember somebody telling me that what had happened was that they had a site handover scheduled right at lift-off! And nobody caught it."]
[Jack's memory is not quite accurate, although the problem was, in part, due to procedures on the ground. The following has been extracted from the Apollo 17 Mission 5-Day Report: "On lunar module ascent, two-way lock with the lunar module transponder was lost. This resulted in a 4-minute loss of uplink voice, and tracking data during ascent. It was necessary to have the Command Module Pilot pass comments from the ground to the lunar module crew during this period. The initial loss of lock was attributed to attenuation by the lunar module (engine) plume. Communications should have been re-established in less time (than 4 minutes). A review of data indicates that a normal re-acquisition by Goldstone should have been attempted earlier. Approximately 4 minutes after lunar module lift-off, a normal re-acquisition was accomplished."]
[According to Apollo 7 astronaut Walter Cunningham in his book "The All-American Boys" Gene's last words on the Moon were "Let's get this mother out of here." During the mission review in Santa Fe, Gene was surprised not to hear those words but it seems likely to me that what he was remembering was his "Now, let's get off." at 188:01:25 and that, in later tellings, the wording changed to the more colorful version Cunningham quotes. I have discussed this matter with Andrew Chaikin, who is another aficionado of the audio tapes, and we agree on the interpretation given here. My thanks to William Bianco for reminding me about this issue.]
188:01:40 Cernan: We're on our way, Houston!