One Small Step

The lunar module was falling gently towards the Moon, its spidery legs stretched out beneath it. Through a small triangular window, Neil Armstrong watched the grey surface coming closer.

Then a yellow warning light flashed on the computer, and an alarm sounded in the astronauts' headsets.

Neither Armstrong nor Buzz Aldrin, standing beside him, recognised the code. They were only minutes away from the most dangerous landing anyone had ever tried, nearly 400,000 kilometres from home, and the computer was telling them something was wrong.

The journey

Apollo 11 had launched four days earlier, on 16 July 1969, from the Kennedy Space Center in Florida. The Saturn V rocket that carried it was taller than a thirty-storey building, and the most powerful machine ever built at that time. Crowds lined the beaches to watch it rise on a pillar of fire.

On board were three astronauts. Neil Armstrong, the commander, was a quiet engineer and test pilot. Buzz Aldrin, the lunar module pilot, was an expert on how spacecraft meet and dock in orbit. Michael Collins would fly the command module.

They travelled in two spacecraft joined together. The command module, called Columbia, would carry them there and back. The lunar module, called Eagle, was a strange, lightweight craft, built only to fly in space. It could land on the Moon, but it could never return to Earth.

After three days, they went into orbit around the Moon. On 20 July, Armstrong and Aldrin climbed into Eagle and separated from Columbia. Collins stayed behind, circling alone.

Alarms and boulders

Now, as Eagle descended, the alarm went off. Then again.

In Mission Control in Houston, a young engineer named Steve Bales had seconds to decide. With the help of a colleague, Jack Garman, who had studied the codes, he worked out that the computer was simply overloaded with tasks. It was still doing the important work of landing. The answer went up to the spacecraft: carry on.

Then came a second problem. As the ground came close, Armstrong saw that the computer was guiding them towards a large crater surrounded by boulders, some as big as cars. Landing there could tip Eagle over.

Calmly, he took partial control and flew the craft onwards, skimming over the rocks, searching for a smooth place. Aldrin called out their height and speed. In Houston, the room fell silent as the fuel figures dropped. They had very little left.

Then Aldrin called out that he could see their shadow, and dust kicking up from the surface. A light came on: contact.

A moment later, Armstrong's voice came across the radio.

"Houston, Tranquility Base here. The Eagle has landed."

In Mission Control, people who had been holding their breath for minutes let it out at last, and the room broke into cheers.

The step

It was several hours before the astronauts were ready to go outside. They put on their bulky spacesuits and backpacks, and opened the hatch.

Armstrong backed slowly down the ladder. A camera fixed to Eagle sent fuzzy black-and-white pictures back to Earth. Hundreds of millions of people around the world were watching, on televisions in living rooms, in shop windows, in town squares.

He stepped off the footpad onto the Moon, and said:

"That's one small step for man, one giant leap for mankind."

Armstrong later said he had meant to say "one small step for a man", and that the little word may have been lost in the radio crackle. Either way, the line has been remembered ever since.

About twenty minutes later, Aldrin joined him. Looking around at the bare grey plains under a black sky, he described the view as "magnificent desolation".

On the surface

The two men spent about two and a half hours outside. They found that walking was easier with a kind of bouncing lope, because the Moon's gravity is only about one sixth of Earth's. Their boots left sharp prints in the fine, powdery dust, prints that may last for a very long time, because there is no wind or rain to wear them away.

They set up a flag, and scientific instruments: a device to measure moonquakes, and a mirror to reflect laser beams fired from Earth, so that scientists could measure the distance to the Moon very precisely. That mirror is still used today. They collected rocks and soil to bring home.

On one leg of Eagle was a metal plaque. It read: "Here men from the planet Earth first set foot upon the Moon July 1969, A.D. We came in peace for all mankind."

Meanwhile, Collins circled overhead in Columbia. Each time he passed behind the Moon, he was cut off from all radio contact with Earth, more alone than perhaps any human had been before. He later wrote that he did not feel lonely, but full of awareness and satisfaction.

Home

The next day, Eagle's upper half lifted off from the Moon and joined Columbia in orbit. All three men began the long journey home.

On 24 July 1969, Columbia splashed down safely in the Pacific Ocean. Because no one yet knew for sure whether the Moon might carry unknown germs, the astronauts spent about three weeks in quarantine before they could hug their families.

Around 400,000 people had worked on the Apollo programme: engineers, scientists, seamstresses who sewed the spacesuits, mathematicians who checked the paths. The three astronauts always said the success belonged to all of them.

Since then, only twelve people have ever walked on the Moon, all of them between 1969 and 1972. But on that July night, for the first time, human beings stood on another world, and looked back at their own small blue planet, hanging in the dark.

Want to read more?

Andrew Chaikin's A Man on the Moon tells the story of every Apollo mission. James R. Hansen's First Man is the official biography of Neil Armstrong, and Michael Collins's own book, Carrying the Fire, is one of the best accounts ever written by an astronaut.