JULY 1969, A.D.

WE CAME IN PEACE FOR ALL MANKIND.”

One of the first things Neil did on the surface was take a sample of the lunar soil in case we had to terminate our moon walk early. Now he started working with his scoop and collection box while I set up the metal foil “window shade” of the solar wind collector. The moon was like a giant sponge that absorbed the constant “wind” of charged particles streaming outward from the sun. Scientists back on Earth would examine the collector to learn more about this phenomenon and, through it, the history of the solar system.

As we removed the flag from the equipment compartment at the base of the LM, I suddenly felt stage fright. Since childhood I’d been fascinated by explorers planting flags on strange shores. Now I was about to do the same thing, but on the most exotic shore mankind had ever reached.

Of all the jobs I had to do on the moon, the one I wanted to go the smoothest was the flag raising. Bruce had told us we were being watched by the largest television audience in history, over a billion people. Just beneath the powdery surface, the subsoil was very dense. We succeeded in pushing the flagpole in only a couple of inches. It didn’t look very sturdy. But I did snap off a crisp West Point salute once we got the banner upright.

I noticed that the legs of my spacesuit were smeared with sooty dust, probably from the LM footpad. When we removed our helmets back inside Eagle, there would be no way we would be able to keep from breathing some of that dust. If strange microbes were in this soil, Neil and I would be the first guinea pigs to test their effects.

Bruce told us that President Richard Nixon wanted to speak to us. More stage fright. The president said, “For one priceless moment, in the whole history of man, all the people on this Earth are truly one.”

I looked high above the dome of the LM. Earth hung in the black sky, a disk cut in half by the day‑night terminator. It was mostly blue, with swirling white clouds, and I could make out a brown landmass, North Africa and the Middle East. Glancing down at my boots, I realized that the soil Neil and I had stomped through had been here longer than any of those brown continents. Earth was a dynamic planet of tectonic plates, churning oceans, and a changing atmosphere. The moon was dead, a relic of the early solar system.

Time was moving in spasms. We still had many tasks to accomplish. Some seemed quite easy and others dragged on. It took me a long time to erect the passive seismometer (the “moonquake” detector). We were supposed to level it by using a BB‑type device centered in a little cup. But the BB just swirled around and around in the light gravity. I spent a long time with that, but it still wouldn’t go level. Then I looked back, and the ball was right where it should be.

“You have approximately three minutes until you must commence your EVA termination activities,” Bruce told us. Our time walking on the moon was almost over.

I was already on the ladder when Neil reminded me about the mementos we had planned to leave on the moon. From a shoulder pocket I removed a small packet that held the two Soviet medals and the Apollo 1 patch, as well as a small gold olive branch, one of four we’d bought. We’d given the other three to our wives as a way of joining them to our mission. The packet also contained the tiny silicone disk marked “From Planet Earth” and etched with goodwill messages from the leaders of 73 nations, including the Soviet Union. I tossed the pouch onto the soil among our jumbled footprints. Once more I thought of Ed White. Only 10 years before we had talked about becoming rocket pilots. In a way, Ed had come with me to the moon.

They stowed 40 pounds of moon rocks, left behind their life support back packs and overshoes, and ate and slept on the surface. Aldrin:

Finally it was time to eat and sleep. After we had snacked on cocktail sausages and fruit punch, I stretched out on the deck beneath the instrument panel, and Neil propped himself across the ascent engine cover. With the windows shaded, the LM grew cold. Neil was having trouble getting to sleep because of the glare of Earth reflected through our telescope on his face. We had moon dust smeared on our suit legs and on the deck. It was like gritty charcoal and smelled like gunpowder from the fireworks I’d launched so many years before on the New Jersey shore.

Seven hours later we prepared for ascent. There was an almost constantly active three‑way loop of radio traffic connecting Columbia, Eagle, and Mission Control. We discovered during a long checklist recitation that the ascent engine’s arming circuit breaker was broken off on the panel. The little plastic pin simply wasn’t there. This circuit would send electrical power to the engine that would lift us off the moon. Finally I realized my backpack must have struck it when I’d been getting ready for my EVA.

Neil and I looked at each other. Our fatigue had reached the point where our thoughts had become plodding. But this got our attention. We looked around for something to punch in this circuit breaker. Luckily, a felt‑tipped pen fitted into the slot.

At 123 hours and 58 minutes GET, Houston told us, “You’re cleared for takeoff.”

“Roger,” I answered. “Understand we’re number one on the runway.”

I watched the DSKY numbers and chanted the countdown: “Four, three, two, one… proceed.” Our liftoff was powerful. Nothing we’d done in the simulators had prepared us for this amazing swoop upward in the weak lunar gravity. Within seconds we had pitched forward a sharp 45 degrees and were soaring above the crater fields.

“Very smooth,” I called, “very quiet ride.” It wasn’t at all like flying through Earth’s atmosphere. Climbing fast, we finally spotted the landmark craters we’d missed during the descent. Two minutes into the ascent we were batting along at half a mile per second.

Columbia was above and behind us. Our radar and the computers on the two spacecraft searched for each other and then locked on and communicated in a soundless digital exchange.

Four hours after Neil and I lifted off from the Sea of Tranquillity, we heard the capture latches clang shut above our heads. Mike had successfully docked with Eagle. I loosened the elastic cords and reached around to throw more switches. Soon Mike would unseal the tunnel so that Neil and I could pass the moon rocks through and then join Mike in Columbia for the long ride back.

I hadn’t slept in almost 40 hours and there was a thickness to my voice and movements. Still I could feel a calmness rising inside me. A thruster fired on Columbia, sending a shiver through the two spacecraft.

Seven hours later we were in our last lunar orbit, above the far side, just past the terminator into dawn. We had cast Eagle’s ascent stage loose into an orbit around the moon, where it would remain for hundreds of years. Maybe, I thought, astronauts will visit our flyweight locomotive sometime in the future. Mike rode the left couch for the trans‑Earth injection burn. Our SPS engine simply had to work, or we’d be stranded. The burn would consume five tons of propellant in two and a half minutes, increasing our speed by 2,000 miles per hour, enough to break the bonds of the moon’s gravity.

We waited, all three of us watching the DSKY. “Three, two, one,” Mike said, almost whispering.

Ignition was right on the mark. I sank slowly into my couch. NASA’s bold gamble with Lunar Orbit Rendezvous had paid off. Twenty minutes after the burn we rounded the moon’s right‑hand limb for the final time.

“Hello. Apollo 11, Houston,” Charlie Duke called from Earth. “How did it go?”

Neil was smiling. “Tell them to open up the LRL doors, Charlie,” he said, referring to our quarantine in the Lunar Receiving Laboratory.

“Roger,” Charlie answered. “We got you coming home.”

The moon’s horizon tilted past my window. Earth hung in the dark universe, warm and welcoming.