This is 99% invisible. I'm Roman Mars.

The moment is at hand the countdown reaches zero.

In 1957, a few months after the Soviet satellite Sputnik became the first human object in space.

The United States launched Explorer 1.

Explorer is in orbit.

Broadcasting to the world is coded scientific data, cosmic ray intensity, meteor impact, solar radiation.

These are the dry facts that will help carry a man ever farther into the age of space.

And with that, the space race was underway and the two world powers began

launching more and more satellites every year. A lot of these early missions

failed before they ever made it into orbit.

That's producer Emmett Fitzgerald.

But there were successes, and little by little space started to fill up with human-made objects.

By the summer of 1961, there were 115 satellites circling the Earth.

And it was during that summer that the U.S US launched an unmanned rocket carrying the transit 4A satellite.

And about two hours after launch, the rocket blew up.

It was the first known object to unintentionally explode in space,

and it created about 300 fragments of totally useless space junk. Some of these pieces got pulled into the atmosphere and burned up, but around

200 are still up there today.

At the time most people weren't all that concerned about a few bits of metal floating around in the vastness of space.

I think the general feeling was that space was big and that we could put objects satellites up into space without really having any consequences to that.

This is Hugh Lewis, a space junk expert at the University of Southampton.

Back in the early days of the space age, it wasn't seen as a problem.

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