Among its notable accomplishments, Apollo 12 is famous for having returned no video of Pete Conrad and Al Bean exploring the lunar surface. Though the lunar landing crew carried a colour TV camera to bring their mission to the world live, transmissions failed after the lens was exposed to an excess of sunlight. The camera mishap came up when I met Bean in November, and he offered by far the best retelling of the story I’ve every heard.
Conrad and Bean only carried one camera to the Moon to record their surface activities; the crew trained with both a black and white and a colour camera, but ultimately only the latter made it to the Moon. It was stored outside the lunar module Intrepid in the descent stage equipment compartment to capture the astronauts’ descent on to the lunar surface. Which it did; when Conrad eased his way out through the Intrepid’s hatch, the picture was grainy but it was live from the Moon.
That shot remained unchanged, the camera working perfectly, fixed on the LM’s leg so the world could see Bean walk down the ladder as well. Then the crew go to work.
As per the mission plan, it fell to Bean to transfer the camera from its stowed position and set it up in its deployed position on the Moon. In mission control, NASA saw the changing picture as Bean, in his thick EVA gloves, picked up the camera and moved it around. Suddenly, the picture changed. The lunar landscape was replaced by a stark image. The top 20 percent was white and the rest jet black.
Houston Capcom radioed Bean about the change in picture. “Al, we have a pretty bright image on the TV; could you either move it or stop it down?”
Bean replied thinking out loud about how to fix the problem. “Okay, I’m going to have to stop it down… The problem is the LM is very reflective… Let me go over here further to the side…” But troubleshooting didn’t help. The image in Houston remained an abstract black and white. After a few minutes of fiddling, Bean offered another possible solution: “Well, I’ll tell you what let me do, Houston. Let me move it around here back, so the back is to the Sun, and maybe that’ll help. Maybe that’s the way we’re going to have to do it.”
That turned out to be the problem: Bean had inadvertently turned the camera and pointed it towards the Sun. Post-flight tests lent support to this theory. Back on Earth, technicians exposed a camera with an Apollo-type image sensor (properly called a secondary electron conducting vidicon tube) to a bright light. The resulting image was strikingly similar to the one sent back by Apollo 12 after Bean turned it towards the Sun. As confirmation, the Apollo 12 camera was decontaminated, cleaned, inspected, and powered up. The image was the same as it had sent back from the Moon. Then a technician cut a wire, disabling the automatic light-level control circuit. Suddenly the picture returned, but only on the lower portion of the screen. The black part of the image was the undamaged part of the camera.
NASA took measures to ensure future missions didn’t lose their video by the same accident. The training and operational procedures for deploying the camera were changed and a lens cap was added, both to decrease chances of an inadvertent turn towards the Sun or another bright surface. NASA also sent backup cameras on subsequent missions; the same colour camera was the primary unit on Apollo 13 but that mission did carry a black and white backup camera inside the LM just in case.
But even nearly fifty years later, Al Bean can’t escape the episode of the camera. He’s appeared in documentaries explaining just how he was trained to deploy the camera and how it ended up, not by his fault, pointing at the Sun. And when I met him in November it came up again. He told me about getting a little lost walking around the Moon, that he and Conrad sometimes had a hard time keeping themselves pointed in the right direction all the time. He added that since NASA didn’t send them with a working camera, mission control couldn’t do anything to help. Without thinking I said that the story I knew was that the camera had been destroyed when it was turned towards the Sun.
Alan Bean turned to me, completely straight faced, and said, “It wasn’t my fault we had no video. NASA didn’t send us with a camera they sent us with a solar telescope so I pointed it at the Sun like I was supposed to.” Then he paused and thought for a second and added, “Now why didn’t I think of that line 40 years ago!”