Talk:Mission and Event Timers
Did we actually find a source for the Event and Mission timers not running before launch? If so, we should edit the Mission Timer info to not say that you can use the Event Timer for a countdown clock :). Mark Grant 16:11, 2 December 2007 (PST)
According to the AOH Vol. 2 the Event Timer is not running during prelaunch:
The Mission Timer is working and at least once reset and started during prelaunch. It's currently unknown if it's set to a meaningful value reflecting the countdown clock before launch.
It's a frequently asked question how the astronauts determined the countdown time since they weren't be able to use the Event Timer and probably not used the Mission Timer. The AGC clock would be a possibility if TEPHEM is the time of launch, but this is quite remote, so perhaps they just used ground communication and their wrist watches. --Tschachim 04:01, 3 December 2007 (PST)