The terminal countdown for the launch of Apollo 11 began at 7:00 P.M. EDT on July 14, 1969 after a 16 hour scheduled hold. At that point, the mission was at T-28 hours. The hours don't add up because there were two more scheduled holds to come; 11 hours on the 15th and 1 hour 32 minutes on the morning of the 16th. It was a day for both the crew and the launch team to rest up for the final push:
The Apollo 11 astronauts spent a quiet day at their moonport. Neil Armstrong, Mike Collins and Buzz Aldrin spent most of the day in the astronaut apartments at the Kennedy Space Center. Most of the Apollo launch team also took at least part of the day off for some rest. The Countdown was stopped for 16 hours -- as scheduled -- to allow a pause in the hectic preparations. In the "firing room" of the launch control center, fewer than 100 people kept watch over the giant rocket. That number would grow to 600 at blastoff time.
I don't understand the concept of a "scheduled hold".
Posted by: Rob | July 15, 2009 at 08:16 AM
From what I understand it's built in time to do any fixes that may come up during the countdown and still be able to keep the scheduled launch time. In the days preceding the launch there are hundreds of tests in addition to the ramping up of the many systems. Any number of little things could go wrong that can be fixed if they have a little time. It also gives people a little break if there is nothing that they have to repair or work on during the hold.
Posted by: Dave E. | July 15, 2009 at 08:55 AM