Magnificent Desolation_ The Long Journey Home From the Moon - Buzz Aldrin [7]
Charlie was telling us that it was showtime. Descent Orbit Insertion (DOI), would take us on an initial coasting descent to within eight miles of the lunar surface, just slightly higher than most commercial aircraft fly over Earth. The DOI burn lasted less than thirty seconds. I looked out the triangular window closest to me and could see the surface of the moon rolling by. The craters were becoming larger and more distinct, their beige color taking on a chalky gray appearance. We continued flying above the terrain until we again heard Charlie Duke. “Eagle, Houston,” Charlie sounded controlled but excited. “If you read, you’re go for powered descent. Over.”
Because of the static in our headsets, Charlie’s words were garbled, but fifty miles above us, Mike Collins heard them clearly and relayed the message: “Eagle, this is Columbia” he said calmly. “They just gave you a go for powered descent.” With no video monitor onboard, Mike could not see the LM or watch the proceedings, but he could listen in on the radio communications. It was a good thing he was paying attention.
Neil nodded as we acknowledged the implications of Charlie’s message. Inside my helmet, I was grinning like we had just won the biggest race of all time. In eleven minutes we were going to set the Eagle down for a landing unlike any other.
NEIL THREW THE switch to ignite the powered descent burn. Oddly, we could barely hear it or feel any sensation when a hot orange plume poured out of the engine into the black space below us. Had we not seen the change on the instrument panel in front of us, we might not have even known that the engine had ignited and was whisking us downward. But downward we were going, and rapidly, too. Through the window on my right, I could see the moonscape seemingly rising toward us.
I turned on the 16-millimeter movie camera that was located in my window to film our descent to the lunar surface. I also switched on my microphone to voice activated mode (VOX). Neil didn’t really care whether or not we were on an open mike as we descended, but I did, so I turned the setting to VOX. There were simply too many things going on to have to worry about a “push to talk” microphone system as we came down. Looking back, I’m glad that I left the mike on. Millions of people on Earth listened in to the static-filled radio transmissions between Mission Control in Houston and us as we descended. Some of our transmissions were barely distinguishable. That was one problem we had not anticipated in our hundreds of hours of working in the simulator back on Earth—it hadn’t really occurred to us that we wouldn’t be able to hear instructions from Mission Control, but we were catching enough to stay focused and keep going.
Five minutes into our powered descent, everything was looking good as we passed through about 35,000 feet on our altitude readout. Suddenly an alarm flashed on the screen in front of me.
Neil saw it as well. “Program alarm!” he said instantly to Houston.
Even with our transmissions traveling at the speed of light, it took one and a half seconds each way between the moon and the Earth, causing a three-second delay in all our communications. This meant that Charlie couldn’t respond immediately, so his response was based on our prior communication. Indeed, he was still quite positive.
“It’s looking good to us. Over.”
“It’s a twelve-oh-two.” Neil’s voice included a hint of urgency. “What is it?” Neil said to me. We had never seen a 1202 alarm in our simulations, and in the middle of our crucial eleven-minute landing maneuver, we weren’t about to take out the thick guidance and navigation dictionary we had brought along. Then to Houston, Neil said, “Give us a reading on the twelve-oh-two Program Alarm.”
“Twelve-oh-two,” I called out, the seriousness of the alarm evident