Apollo+40: Program Alarm!

At 102:38:04, Eagle began receiving good data from its landing radar, without which a landing could not be attempted. As LMP Aldrin began incorporating the radar data into the guidance computer's trajectory calculations...

102:38:26 (CDR): "Program alarm."

102:38:30 (CDR): "It's a 1202."

The guidance and computer experts in Mission Control were scurrying; what was the problem? Could Eagle continue? Was an abort called for?

Well, it turns out that one of the last simulations Mission Control went through involved guidance computer program alarms. The guidance "back room" quickly told the Guidance Officer, Steve Bales, that it was a temporary overload condition and that it was safe to proceed. Bales called onto the Flight Director's voice loop in Mission Control: "We're GO on that, Flight."

102:38:42 (CDR): "Give us a reading on the 1202 program alarm."

102:38:53 (CAPCOM): "Roger. We got you...We're GO on that alarm."

At 102:39:14, another 1202 program alarm was triggered. Eagle is still GO!