Gravity pulls all satellites down to Earth.

But in the mid 19 seventies, NASA engineers discovered the massive lump of metal was losing orbit faster than expected.

With Skylab, it seems, they had underestimated the power of the sun.

Once the last astronaut had closed the door behind him, the space station was supposed to orbit the Earth for another 10 years.

Skylab is there, and it's in orbit, and it's essentially a that point.

Been abandoned.

It's it's flying overhead.

People remember that it's there, but it's not being used.

It's it's not act.

What is active during this time is the sun and in a way that nobody had anticipated.

We think of space as a vacuum.

But Skylab orbit was influenced by the Earth's atmosphere.

In the mid 19 seventies, the sun was unusually hot.

The result.

The atmosphere heated up and expanded this created drag on the space station, slowing it down and starting to pull it out of orbit.

NASA had underestimated the impact of solar activity, which had effectively halved its lifespan.

Result.

Skylab would crash back to Earth four years earlier than expected.

Skylab waas A very large chunk of metal, and people kind of understood that this was a thing, that it had taken a giant rocket to put in space.

This is a big thing that's up there, and now it's going to be coming down to buy them time.

NASA looked at ways to keep Skylab in orbit One audacious plan depended on a revolutionary spacecraft that was still in development.

The space shuttle.

The shuttle would carry an Apollo capsule up to Skylab and use the capsules thrusters to boost Skylab into Ah, higher, longer lasting orbit.

So now we have a space station up there.

The atmosphere is expanding faster than we anticipated.

It's putting more drag on Skylab than we anticipated.

And at the same time, down here on Earth, work on the space shuttle is taking place is taking longer than was originally anticipated.

Skylab reentry was getting closer, but the space shuttles launch was delayed.

Eventually, it's realized these things aren't going across.

The Sky lab is gonna come down before the space shuttle starts flowing.

Skylab was going to crash back to Earth years earlier than expected, and where it would land was anyone's guess.

Three.

Idea of dropping it on somewhere like Idaho or Mississippi really got people thinking, however remote, the possibility you had people who were who were selling and buying sky live hard hats Thio to protect them.

You had kind of a general sense of panic that, you know, is this thing going to, ah, land on me?

NASA ENGINEERS WEREn't JUST GOING TO stand by.

Professor Bonnie Dunbar is a former shuttle astronaut, but at the time was a navigation officer at Skylab Mission Control when NASA realized that the shuttle wasn't going to make it on time and that the Skylab was de orbiting faster than anticipated, said, Well, we're going to be responsible about finding a way to de orbit it in a particular place.

Real aim was to ensure that the final entry was over the sea or an unpopulated area tow.

Avoid disaster.

Southern Hemisphere has fewer people and more water, so Bonnie and the team planned for an Indian Ocean splash down.

However, the ailing space station wasn't designed for major course corrections.

All they could do was adjust its angle relative to the atmosphere.

You have the ability to change the orientation of Skylab, but it's very limited, and that's all you have to work with.

At this point, they're controlling the space station.

They're controlling its re entry simply by turning it and increasing the drag.

It's sort of like putting your hand outside the car window and letting the wind hit it.

If it's flat handed, it's going to drive your hand back and that there's a lot of drag.

There'll actually slow you down if it were big enough, but if you put it sideways, it's like a wing.

And so there's not much drag.

Changing Sky Labs angle would influence its speed and how quickly it would lose altitude.

In theory, this gave NASA some control over where and when the station would come down.

But would they be able to bring it down safely?

Yes, America's first space station was falling to Earth five years earlier than anticipated, but NASA engineers were working 24 7 to control where it fell.

We had three mission control teams.

We were each on for eight hours, and we began to control the Skylab 24 hours a day for nine months.

Finally, on July 11th 1979 Skylab started its final descent through the Earth's atmosphere, 16 kilometers up hurdling faster than a speeding bullet.

Space station started to disintegrate.

Several large pieces survived re entry and smashed into parts of western Australia.

But luckily no one was hurt.

However, Australian authorities did find NASA $400 for littering taught us from an engineering point of view as much from its re entry as it was when it was up in orbit.

The Skylab mission was played by engineering problems, but NASA learned vital lessons which have taken space exploration toe whole new frontiers.

Really, everything that we're doing in space flight today is because of what we did with Skylab.

Despite its problems, Skylab was still a hugely successful mission.

Not only did it teach us a lot about what's out there, it taught us a great deal about engineering, too.