With Neil trying to sleep leaning back on the ascent engine cover, I curled up on the bottom of the LM, where I noticed some of the moon dust on the floor. It had a gritty, charcoal-like texture to it, and a pungent metallic smell, something like gunpowder or the smell in the air after a firecracker has gone off. Neil described it as having a ‘wet ashes’ smell.
In my fatigue, I was still thinking about the dust when I noticed something lying on the floor that really did not belong there. I looked closer, and my heart jolted a bit. There in the dust on the floor on the right side of the cabin, lay a circuit breaker switch that had broken off. I wondered what circuit breaker that was, so I looked up at the numerous rows of breakers on the instrument panel without any guard protectors, and gulped hard. The broken switch had snapped off from the engine-arm circuit breaker, the one vital breaker needed to send electrical power to the ascent engine that would lift Neil and me off the moon. During our powered descent, this same engine-arm circuit breaker had been in the closed position, pushed in to engage the descent engine for our landing, and once we touched down we pulled it back out, in the open position, to disengage the circuitry and disarm the engine. Somehow, one of us must have bumped it accidentally with our cumbersome backpacks as we moved around in the cramped space preparing to get out of the LM, or as we came back in. Regardless of how the circuit breaker switch had broken off, the circuit breaker had to be pushed back in again for the ascent engine to ignite to get us back home We reported it to Mission Control and then tried to sleep and forget about it — as if that were possible. But we knew Mission Control would help figure out a solution, and if we could not get that circuit breaker pushed in the next morning when we were ready to lift off, we would have to do something else. For now, they wanted us to leave the circuit breaker out. So, while Neil and I tried to rest, the guys in Houston debated how we could work around that circuit, in case it had to be left open.
When we received our wake-up call from Houston, the question of how to handle the broken circuit breaker had still not been solved. After examining it more closely, I thought that if I could find something in the LM to push into the circuit, it might hold. But since it was electrical, I decided not to put my finger in, or use anything that had metal on the end. I had a felt-tipped pen in the shoulder pocket of my suit that might do the job. After moving the countdown procedure up by a couple of hours in case it didn’t work, I inserted the pen into the small opening where the circuit breaker switch should have been, and pushed it in; sure enough, the circuit breaker held. We were going to get off the moon, after all. To this day I still have the broken circuit breaker switch and the felt-tipped pen Iused to ignite our engines.
From "Magnificent Desolation: The Long Journey Home from the Moon" by Buzz Aldrin with Ken Abraham