The Trouble with Space Junk Horizon


The Trouble with Space Junk

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Transcript


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'Down, I see her. Right cable is down.'

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'OK to go for configuration, Steve.'

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'Thank you, Al.'

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220 miles above the Earth on 12th March 2009,

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was a day like any other on the International Space Station.

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'Two and three stowed.'

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It was mid-morning and I was getting ready to exercise.

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And we were just sort of getting into our mid-morning routine, if you will.

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'OK, Nick. On my way.'

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But then they got an unusual message.

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We got a call that we were having "a red conjunction".

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We were looking around, "What is a red conjunction?"

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Because we hadn't really trained for it.

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A red conjunction is a warning code

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that the space station could be hit by some orbital debris.

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It was a little bit chaotic,

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because this was the first time we had had one of these.

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The space station was travelling at nearly 8km per second.

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The space junk was travelling at the same speed

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in the opposite direction.

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If they hit, the consequences could be catastrophic.

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It gets hit by something relatively small...

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..penetrates, but because of the pressure inside,

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it just forces the modules to open up just like a balloon bursting.

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And that happens extremely quickly,

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with no chance that an astronaut in that module could ever get out.

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'Copy, Al. You're on your way to the station.'

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Nasa was taking no chances

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and scrambled astronaut Sandra Magnus to the Soyuz life raft.

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All she could do then

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was sit and wait.

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And it's either going to hit or it's not going to hit.

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And so worrying about it doesn't help you.

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Was this just an isolated incident

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or was it a sign of a growing threat to life in space...

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..and modern life on Earth?

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'And liftoff.'

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'First stage move. Propulsion performing normally.'

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Space...

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..endless and empty.

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At least that's what we used to think.

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In the last few decades,

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orbits around Earth have become crowded with satellites

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and littered with space junk.

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So space junk is all the stuff that we've launched into orbit

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that no longer serves a useful purpose.

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So it's satellites, it's rocket bodies,

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it's, you know, old gloves.

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It's toolkits that astronauts have accidentally dropped.

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Basically, litter that we've left in space.

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But littering space is much more dangerous than it is on Earth.

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Those objects are going at 17,000 miles an hour.

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And when you're going 17,000 miles an hour,

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it does not take a big piece of debris to ruin your day.

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Satellites are virtually defenceless against high-speed orbital debris.

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And they are crucial to modern life on Earth.

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We are far more connected and far more dependent upon satellites

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than most people really know.

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The ability to make phone calls,

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the way we do it now was just a dream less than 100 years ago.

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We're all connected to the internet.

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Weather satellites, navigation systems,

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it's almost impossible to get lost,

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despite what the guidance says on the GPS about turn left and turn right.

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All of that and more is becoming increasingly vulnerable.

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Unless we tackle the debris problem,

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there is going to be no weather forecast,

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there is going to be no news story from the other side of the world.

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You're not going to be able to turn on the television and see the World Cup.

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But how did space become littered with dangerous debris?

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'Today, a new moon is in the sky.

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'A 23-inch metal spear placed in orbit by a Russian rocket.'

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Space was a pristine environment,

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until the launch of Sputnik in 1957.

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But in the first decades of spaceflight,

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every time a rocket or satellite was launched,

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it left behind some debris.

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No-one thought it was much of a problem until this man,

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Donald Kessler, did some calculations.

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He was working for Nasa in the late '60s and early '70s,

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when he discovered that leaving junk in orbit

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wasn't like dumping junk on Earth.

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People tend to think of orbit like a road through space.

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I mean, as long as you stay on your road, you're not going to get hit.

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It would be more accurate to think of the Earth as being

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one big paved planet.

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And when you want to go someplace,

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you drive in a straight line from one place to another

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and, of course, with no stop lights and no place to stop

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and you're going to be running into each other in all kinds of directions.

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And that's exactly what you've got in orbit.

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So I headed up with an equation where I could write the spatial density,

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its apogee and inclination.

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Then you can do neat things like...

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His calculations predicted that,

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if bits of junk started smashing into each other at such huge speeds...

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If you want to know the flux, the spatial density...

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..they'd create a cascade of collisions

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that would litter orbits with dangerous debris.

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The integral of S squared...

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This became known as the Kessler Syndrome.

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..integrated over the volume.

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In other words, if you never launch anything else in space,

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there will still be this cascading phenomena that continues to grow

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and, actually, it continues until you essentially grind up all the satellites into small dust particles.

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Three passed SV and 26.

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No time critical commanding.

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No satellite conjunctions. Good on step six.

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All data feeds to externals are open and both communication lines to the site are good.

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No applicable sieves or TPs. You're good to execute.

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Copy that, ma'am.

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The prospect of this nightmare scenario was so worrying that,

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in the early '80s,

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the American Air Force started cataloguing space junk.

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The technology only allowed them to track objects

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slightly bigger than a cricket ball.

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Give level one a call on the TTC-56.

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They started at 6,000 pieces.

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And that number grew slowly to 10,000 over the next two decades,

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helped by an international agreement calling for used rocket bodies

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to be returned to Earth and burned up in the upper atmosphere.

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OK, stand by.

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It kept the risk of any major collision very low.

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But in 2007,

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all that changed.

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The Chinese launched a missile

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that took out one of their own defunct old satellites

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in low Earth orbit.

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The American military were under no illusions about what this meant.

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Well, I think they did that because they realised

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that the United States military

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is critically dependent on space.

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And they felt like if they were going to be able

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to effectively respond to whatever challenges they had in the future,

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they needed to develop a way to challenge our space capabilities.

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Basically, there's not a single military operation

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that takes place in the world today

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that is not critically dependent on space capabilities.

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And if space goes away,

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we do not fight as effectively as we would otherwise.

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As Kessler predicted,

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collisions in space are more dangerous than those on the ground.

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As demonstrated in this computer model.

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After the collision, you see quite a compact debris cloud at the start.

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But then, because some of the fragments are thrown into higher orbits

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and some are thrown into lower orbits, the speed is different.

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So you see the debris clouds stretch out and it forms this ring.

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Now, because the Earth is not spherical,

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it causes that debris ring to start to stretch out.

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It moves the orbits around the planet.

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So it goes from this kind of compact debris cloud right at the start

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to the situation where all of that debris

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ends up being distributed all the way around the planet.

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Before China took out its old satellite,

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the American Air Force were tracking 10,000 objects

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in their debris catalogue.

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After it, they were tracking an extra 3,000.

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The debris field collisions create

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is a massive concern for the general

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who is in charge of all of America's space operations.

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If you go to war in space, then it becomes a kinetic war.

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You create a debris field that is just unmanageable

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and you can't operate or fly in it.

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So I hope to never go to war in space.

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But at the same time, if we're threatened,

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we have to be able to defend ourselves

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and we have to be able to defend ourselves right now.

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But the debris problem got worse in 2009

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when an Iridium satellite collided

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with an out-of-control Russian Kosmos satellite.

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Now they were monitoring 17,000 pieces of junk.

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At that number, Kessler's calculations

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were forecasting a major collision on average every five years.

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And really the situation you start to worry about is that's just one event.

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You know, if you start to say,

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"We're going to have one of these events every five years

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"and that each one is going to generate thousands of fragments,"

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then you end up in the situation where it's basically, you know, a lottery,

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in terms of whether or not your satellite is going to be hit.

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We see thousands and thousands of near misses every single day

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as a result of all the junk that we've put up there.

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But that average of one collision every five years

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might not be much of a guide to what happens in the future.

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So let's say that you're on a soccer team

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and your average is one goal per game.

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A 20-game season, you score 20 goals

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because you've scored one goal a game.

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So, of course, you're very reliable.

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However, you could just as well have scored ten goals in two games

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and were useless the other 18 games.

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Your average is the same,

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but the confidence that I have of what you're going to do the next game is going to be much lower.

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I don't know whether or not you're going to have a ten-goal game

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or a zero-goal game.

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The same problem right now having to do with space.

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We know the average.

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We don't know if the next event's going to occur

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in one day or one decade.

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So the stakes couldn't be higher.

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But until last year,

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no-one knew exactly what happened to spacecraft when they collided.

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Until this...

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This is the work of Patti Scheaffer.

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She's a key part of the team that fired a baked bean can-sized object

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into a tank roughly the same size as the upper stage of a rocket.

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And size mattered.

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Well, this was the size of the object.

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It was maybe a little bit shorter

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but, basically, a large hollow object

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is more representative of something that's actually in space,

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like maybe a small satellite or a piece of a small satellite.

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It also had to be a full-scale test.

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Lots of people fire things like that, for instance,

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and many things, many physical phenomenon

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do not scale with size very well.

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So we really wanted to get a full-scale, full-sized test.

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It was the culmination of years of work.

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But it was over in a flash.

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"Is that T minus ten?"

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"Yes, that's T minus ten."

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"Nine, eight..." And then you hear this...

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And the building literally shakes a little bit.

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But I think a lot of it is me, you know, just being freaked out.

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And then you see your screen flash up and it's over.

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All that work is turned into this.

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Travelling at 7km per second...

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the can made a huge mess.

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So this piece of modern art here is what the tank looks like.

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Now, this was the top of the tank.

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Right here, it folded after it flew through the inside.

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But you can see it's all splayed out.

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The intense heat from the explosion vaporised huge chunks of metal.

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And when it condensed and cooled, she made a startling new discovery.

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Flakes of aluminium, which came from bits of the can and the tank.

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They might look benign, but in space they'd be lethal.

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Now that's about, er...

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What is that? 250 milligrams.

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That's a little bit bigger, heavier than a ibuprofen pill.

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And the energy that would have on orbit

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at, say, 14km per second would be, er...

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Well, the momentum would be about the same

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as a hot-loaded .357 Magnum.

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So that's a lot of momentum.

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And the energy would be more like

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a .50-calibre Browning machine gun sniper round.

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So if you're going to think about how dangerous this is on orbit,

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think .357 Magnum, .50-calibre sniper round.

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Somewhere in there.

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And she discovered that the collision generated

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hundreds of these flakes.

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No-one knew that vaporised metal could be so dangerous.

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So if there are many more particles produced than we thought,

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10 times, 100 times, 1,000 times more,

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then it has a snowball effect,

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because each one of those particles,

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if there's ten times more, there could be ten times more strikes.

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And each one of those makes ten, so that's ten times ten, which is 100.

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If there's 100 times more, then each one of those can make strikes,

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which is 100 times 100, which is 10,000.

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So it snowballs rapidly.

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The question is, how rapidly is it going to snowball?

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And the only way we can know that

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is to know how many of these particles we can't see

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are actually made.

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But if there are more objects in orbit than previously thought,

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there should be more bullet-sized holes

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in the biggest thing up there...

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..the space station.

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'The thing we showed you is still in the socket caddy when you get there.'

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'It'll be right of the front module. It'll be right of the front module.'

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'You can see almost everything from that vantage point.'

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Astronaut Jim Reilly was on a spacewalk

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to repair an external radiator on the station

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when he spotted something he had never seen before.

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And as we're tilting back, we're going past this radiator.

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I noticed right out on the end of it,

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there were three what looked like bullet holes

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about the size of a 7.62 millimetre round.

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And it's about the size of my thumb. Three of them, just about that size.

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There was a fourth hole on the flight immediately behind mine.

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A fellow named Rick Mastracchio was working on the same area.

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And down by Rick, there's a fourth bullet hole on there.

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The space station can absorb hits from small pieces of junk

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because it has a specially constructed hull

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made up of an ingenious layering system called a Whipple shield.

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What you see here is a mock-up of the Columbus module

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of the European Space Agency,

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which is on the International Space Station.

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And here you see on the outer surface

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the Whipple shield has been implemented everywhere.

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You see here a cutaway part

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and you can see the outer wall, the bumper,

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then you have some stuffing shown here

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and the inner wall, which is finally supposed to stop the particle.

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The layers absorb and dissipate the energy of any strike,

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but the protection is only effective

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for objects up to one centimetre in size.

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Unfortunately, the American Air Force

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only has the technology to track objects bigger than ten centimetres,

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slightly bigger than a cricket ball.

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And that leaves a huge and worrying gap in the space station's defences.

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Objects between one centimetre and ten centimetres, roughly,

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they can neither be avoided nor shielded.

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So there is a dark risk that remains

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even for the International Space Station.

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If the space station was hit by a piece of debris

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of this kind of size...

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..it could be devastating.

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So the space station is a pressurised module.

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That means the pressure inside is greater than the pressure outside.

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It's a vacuum outside the space station.

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And the equivalent down here is a balloon.

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You know, you blow air into a balloon,

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the pressure is greater inside the balloon than outside the balloon.

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And we all know what happens if you stick a pin into a balloon.

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If you look at that balloon bursting in slow motion,

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as the pin goes in, the balloon unzips.

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And that's one of the things that could happen on the station.

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It gets hit by something relatively small, penetrates,

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but because of the pressure inside,

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it just forces the modules just to open up,

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just like a balloon bursting.

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And that happens extremely quickly,

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with no chance that an astronaut in that module could ever get out.

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The space station can manoeuvre out of the way

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of any bigger pieces of junk.

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But as astronaut Sandra Magnus knows,

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it's not like turning the wheel of a car.

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You have to program the kind of burn you want to do.

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You have to program the manoeuvre

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the station needs to get to do the kind of burn you want to do

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based on which jets you're using.

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It takes several days.

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They may have gotten it down faster than that,

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but it's not just, "OK, flip a switch, let's move the station."

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It's not that straightforward.

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In 2014, the station had to move three times

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to avoid large chunks of space debris.

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But as Sandra Magnus discovered in March 2009,

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sometimes there's not enough time to move the station.

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It was mid-morning and I was getting ready to exercise

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and we were just sort of getting into our mid-morning routine, if you will.

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And we got a call that we were having "a red conjunction."

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We were looking around, "What is a red conjunction?"

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Because we hadn't really trained for it.

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A red conjunction is a warning code

0:23:380:23:40

that the space station could be hit by some space junk.

0:23:400:23:43

This warning is only issued when there's no time to move the station.

0:23:450:23:49

It wasn't predicted.

0:23:510:23:53

It was a little bit chaotic

0:23:540:23:56

because this was the first time we had had one of these.

0:23:560:23:59

'Copy, Al. You're on your way.'

0:23:590:24:01

Ground Control were tracking a 13cm chunk

0:24:010:24:04

of a Delta II rocket body,

0:24:040:24:06

about the size of a CD, apparently heading straight for the station.

0:24:060:24:12

And Sandra was sent to the Soyuz capsule,

0:24:120:24:14

the space station's life raft,

0:24:140:24:16

in preparation for a possible evacuation.

0:24:160:24:19

When the Soyuz docks to station, it's put in sort of a sleep mode,

0:24:200:24:25

because you really don't need it while you're on station,

0:24:250:24:28

because it's, you know, your delivery vehicle

0:24:280:24:30

and your go home vehicle.

0:24:300:24:32

But when you're getting ready to evacuate from the station,

0:24:320:24:35

whether it's nominal or a contingency,

0:24:350:24:37

you have to power all that stuff up.

0:24:370:24:38

And there's a certain sequence of things you have to go through to do that.

0:24:380:24:42

But she wasn't panicking.

0:24:500:24:52

It's either going to hit or it's not going to hit.

0:24:520:24:55

And so worrying about it doesn't help you.

0:24:550:24:58

All you have to do is just prepare everything that you need to prepare

0:24:580:25:01

so that, if it hits, then you're in the best possible configuration.

0:25:010:25:05

And if it doesn't hit, well, then, you just go and do it anyway.

0:25:050:25:08

The Soyuz has a small window.

0:25:100:25:12

And as she sat and waited, she couldn't stop herself looking out.

0:25:130:25:18

So I'm looking out the portal thinking, "Oh, maybe I can see it."

0:25:200:25:23

You know, your view is like this, right?

0:25:230:25:26

It's like looking out of a peephole of a door.

0:25:260:25:28

I was laughing to myself, "Go on, there's no way."

0:25:280:25:30

Because if I saw it, it would be really bad, because it'd be right there.

0:25:300:25:34

Fortunately, the junk sailed by and the station was undamaged.

0:25:360:25:40

But the crisis did force the astronauts and Nasa

0:25:400:25:43

to re-evaluate what they would do if it happened again.

0:25:430:25:47

We got through it. It was all good.

0:25:510:25:52

So it wasn't that everybody didn't know what's needed to be done.

0:25:520:25:55

But it's like, what order do you communicate?

0:25:550:25:57

What's the most important thing you communicate? Who communicates what to who?

0:25:570:26:01

So there was a lot of refinement that needed to happen

0:26:010:26:03

and so we instituted that after this.

0:26:030:26:05

'OK, hatch opened and stowed.'

0:26:110:26:14

Since that near miss in 2009,

0:26:180:26:21

the amount of trackable orbital debris has gone up by over 20%

0:26:210:26:26

to 22,000 pieces.

0:26:260:26:30

'Before receiving, gate closed and locked.'

0:26:360:26:40

But scientists calculate that there are hundreds of millions of pieces of debris

0:26:420:26:46

that are too small to track

0:26:460:26:48

hurtling round in the orbits close to Earth.

0:26:480:26:51

'How about just one more check on the reel?'

0:26:510:26:54

Most of them don't present any threat to the space station.

0:26:540:26:59

But they do to the people who live and work up there...

0:26:590:27:02

..the astronauts.

0:27:040:27:06

For emergency doctor Kevin Fong,

0:27:180:27:20

who worked at Nasa in their human spaceflight programme,

0:27:200:27:24

astronauts are at their most vulnerable on the spacewalk.

0:27:240:27:28

'OK, we checked all four systems.'

0:27:330:27:36

'Modulation all four and clean with the go.'

0:27:380:27:40

These guys are out there tumbling around the Earth

0:27:420:27:45

holding onto the space station,

0:27:450:27:47

travelling at 17,500 miles an hour

0:27:470:27:50

250 miles off the ground

0:27:500:27:53

with nothing between them and death

0:27:530:27:55

but this multilayered suit and a visor.

0:27:550:27:57

I mean, that's... that's walking in space.

0:27:570:28:01

'Oh, my goodness, something's fallen out.'

0:28:010:28:04

Throw space junk travelling at similar velocities into the mix

0:28:060:28:09

and the dangers start to get bigger.

0:28:090:28:12

At that speed,

0:28:140:28:16

something as small as a fleck of paint could be life-threatening.

0:28:160:28:21

Just how dangerous has been tested in this special lab

0:28:250:28:28

at the University of Kent.

0:28:280:28:29

This strange-looking assembly of pipes and tubes

0:28:370:28:41

is actually one of the most powerful guns in Britain.

0:28:410:28:45

It can fire objects at roughly ten times the speed of a bullet.

0:28:490:28:54

But today, they're not firing anything as big as a bullet.

0:28:570:29:01

This tiny one-millimetre steel ball is what most space junk looks like.

0:29:060:29:11

In space, small is what's frequent. Large is not very common.

0:29:120:29:16

The ball wrapped in wax

0:29:230:29:25

and similar in size to a tiny piece of debris

0:29:250:29:28

or a fleck of hardened paint is loaded.

0:29:280:29:31

It's the most likely kind of thing to hit an astronaut on a spacewalk.

0:29:340:29:39

'237 in lift.'

0:29:420:29:44

'OK, I am ready to receive it.'

0:29:440:29:47

One of the most vulnerable parts of the spacesuit

0:29:490:29:52

is the astronaut's visor.

0:29:520:29:55

This is a piece of plastic, a polycarbonate,

0:29:580:30:01

which is typically used in space,

0:30:010:30:03

for example as a shield across the visor of the helmet

0:30:030:30:06

an astronaut might wear.

0:30:060:30:08

So he'd be looking out through it, protecting him from the environment.

0:30:080:30:11

What we're going to do with it here is we are going to put it in the gun

0:30:110:30:14

and fire one of our very small particles at 14,000 miles an hour towards it.

0:30:140:30:18

The polycarbonate is the same thickness as the visor.

0:30:230:30:26

So would the visor survive?

0:30:370:30:39

So this is our polycarbonate after the impact experiment.

0:30:430:30:47

So our one-millimetre object travelling at 14,000mph

0:30:470:30:51

has punched straight through the front.

0:30:510:30:54

At the back, there's a slightly larger whole.

0:30:540:30:56

So it's gone through and removed material from the rear surface.

0:30:560:30:59

And that's kept on going and hit what's on the far side,

0:30:590:31:01

potentially an astronaut.

0:31:010:31:03

'OK to go. I have my gate closed and locked.'

0:31:050:31:08

'With that you are go to release the cutters from the internal bearing.'

0:31:090:31:13

The visor's going to be almost non-existent as an obstacle.

0:31:140:31:17

The tiny amount of that energy,

0:31:190:31:21

a fraction of that energy that particle has gets taken up by shattering the visor.

0:31:210:31:24

And in terms of what it would look like to the astronaut,

0:31:240:31:27

well, it's probably going to be the last thing that they see.

0:31:270:31:29

The energy contained within a single fleck of paint

0:31:330:31:36

travelling at these enormous velocities,

0:31:360:31:38

it is much more akin to the energy you see

0:31:380:31:41

contained within a high explosive.

0:31:410:31:43

For astronauts like Jim Reilly, who's walked in space five times,

0:31:540:31:58

the dangers of space junk are part of the job.

0:31:580:32:01

You know, at some point, you get hit by something of any size,

0:32:040:32:07

it's pretty much game over.

0:32:070:32:09

But, you know, we accept those risks even here on Earth.

0:32:090:32:12

You know, you can get hit by a bus and it's just, it's your day, right?

0:32:120:32:16

So you accept that.

0:32:160:32:18

'Good to go to close the thermal hatch.'

0:32:180:32:20

Of course, the astronaut's suit

0:32:200:32:22

presents a much bigger target than the visor.

0:32:220:32:24

But that's more protected.

0:32:240:32:26

'Get all the routing back to the structure itself.

0:32:260:32:29

'Are you good on that?'

0:32:290:32:32

It has a layering system that helps slow down any small objects

0:32:320:32:35

that might pierce the fabric.

0:32:350:32:37

And it also has a built-in safety mechanism.

0:32:390:32:41

The suit can sustain a hole somewhere between an eighth and a quarter of an inch

0:32:430:32:48

and that will still have enough volume within the oxygen tanks

0:32:480:32:51

to give you about 15 minutes to get back into the airlock.

0:32:510:32:55

The problem on the station, though, is that you can be 15 minutes away and further

0:32:550:32:59

when you're doing some of your work.

0:32:590:33:01

'Your left hand is off just now.'

0:33:040:33:05

'OK, captain, complete.'

0:33:090:33:12

ASTRONAUTS TALK INDISTINCTLY

0:33:140:33:17

Spacesuit is kind of a bit of a misnomer.

0:33:190:33:23

It's not a suit.

0:33:230:33:24

It's the world's smallest spacecraft.

0:33:240:33:27

You depend upon it entirely for your life,

0:33:290:33:32

because inside that suit is an atmosphere that you can breathe,

0:33:320:33:35

a warmth enough to keep you alive

0:33:350:33:39

and something that can repel heat when it's out there.

0:33:390:33:43

FEMALE ASTRONAUT SPEAKS INDISTINCTLY

0:33:430:33:48

And it all looks great and it all looks nice and floaty.

0:33:490:33:52

But actually these are some of the most terrifying moments

0:33:520:33:54

in all of human space exploration.

0:33:540:33:56

This is the maximum exposure that an individual can have out there.

0:33:560:34:00

This is where they are stripped of all of the protections

0:34:000:34:03

that have been engineered over years.

0:34:030:34:06

It's hard to think of an environment or a situation

0:34:080:34:11

in which you would be more vulnerable.

0:34:110:34:13

MALE ASTRONAUT SPEAKS INDISTINCTLY

0:34:130:34:18

Up till now, no astronaut has ever come to grief in a spacewalk.

0:34:210:34:25

But for some scientists, the past is no guide to the future.

0:34:280:34:33

When the space age started, Nasa designed the spacesuits

0:34:330:34:37

so that the astronauts could survive impacts of very small dust.

0:34:370:34:41

But as the space age has gone on and bits of paint are flaked away from the outside of spacecraft

0:34:410:34:46

or sometimes a disused satellite explodes and showers space with very fine debris,

0:34:460:34:51

there is more and more debris about the size we've been shooting here today.

0:34:510:34:55

Sooner or later in the next decade or two,

0:34:550:34:57

an astronaut will be struck by something this size.

0:34:570:35:00

But maybe in the future,

0:35:070:35:09

people won't have to risk their lives on the final frontier.

0:35:090:35:12

At the European Space Agency's lab in Holland,

0:35:150:35:19

Dr Andre Schiele is suiting up

0:35:190:35:22

to test the next generation of astronaut.

0:35:220:35:24

He's wearing a high-tech sleeve,

0:35:310:35:33

which is remotely linked to a robot arm.

0:35:330:35:35

Every movement he makes with his hand and arm

0:35:370:35:40

is mimicked by the robot.

0:35:400:35:42

In space, it's a very hostile environment for humans to be

0:35:450:35:49

for several reasons.

0:35:490:35:51

There is debris that can hit astronauts

0:35:510:35:53

when they are doing activities outside.

0:35:530:35:55

If a robotic system is struck by a small part,

0:35:550:35:58

it will probably break,

0:35:580:35:59

but we are not facing life loss.

0:35:590:36:02

So it is much safer to do this

0:36:020:36:04

and we can actually control those robotic systems

0:36:040:36:06

from either inside the safe and shielded environment of the space station

0:36:060:36:10

or even from the ground.

0:36:100:36:12

This cutting-edge technology is still being developed

0:36:140:36:17

and won't come online for a number of years.

0:36:170:36:20

But even when it does,

0:36:200:36:22

Dr Schiele doesn't envisage replacing humans in space.

0:36:220:36:25

We strongly believe at Esa

0:36:280:36:30

that the combination of astronauts and robots

0:36:300:36:33

can be the most powerful one.

0:36:330:36:35

Where not one replaces the other,

0:36:350:36:38

but every system exploits its optimal characteristics.

0:36:380:36:41

So a robot is very good at repeating tasks,

0:36:430:36:45

at doing tasks in very hostile environments.

0:36:450:36:48

And humans are very good at planning tasks,

0:36:480:36:50

at understanding random situations.

0:36:500:36:53

So with the system that we show here, in the telerobotics lab at Esa,

0:36:530:36:57

we are combining the human intelligence

0:36:570:36:59

with the preferences of a robotic manipulator by tele manipulation.

0:36:590:37:04

But orbital debris threatens life on Earth as well as in space.

0:37:150:37:19

And that's because modern life

0:37:220:37:24

is increasingly dependent on satellite technology...

0:37:240:37:28

..from GPS

0:37:310:37:33

to television

0:37:330:37:36

to the weather forecast.

0:37:360:37:38

And in the future,

0:37:390:37:41

we're only going to get more dependent on space technology.

0:37:410:37:44

Our use of space is going to grow.

0:37:490:37:52

We're already relying on many services

0:37:520:37:55

that are provided by satellites already.

0:37:550:37:58

That situation is unlikely to change.

0:37:580:38:00

You know, we're only going to place more demands

0:38:000:38:03

on satellites into the future.

0:38:030:38:06

And, you know, if that happens in combination with a growing debris problem,

0:38:060:38:11

then there're going to be issues arising.

0:38:110:38:14

And that debris problem could be about to get worse.

0:38:180:38:21

Scientists have only recently begun to understand the risks

0:38:220:38:26

of 17 old Russian SL-16 rocket bodies

0:38:260:38:30

orbiting within 50km of each other.

0:38:300:38:32

They're big. About the size of a railway carriage.

0:38:380:38:41

We showed that there is a one in 400 chance over the next ten years

0:38:430:38:47

of two of those SL-16 rocket bodies colliding.

0:38:470:38:52

So you may ask, that doesn't sound like that's too bad.

0:38:550:38:58

I'm not sure how many of you would go and take the subway tomorrow into work

0:38:580:39:02

if there is a one in 400 chance that that subway wasn't going to make it into work.

0:39:020:39:06

So far, those old rocket bodies haven't come close to each other.

0:39:110:39:16

But could there be an even greater danger

0:39:190:39:22

threatening our dependence on space?

0:39:220:39:26

What I'm really more concerned about is kind of like the canary in the mine.

0:39:260:39:29

I don't care about the big breakups.

0:39:290:39:32

I care about the satellites that are failing for unknown reasons

0:39:320:39:35

because, statistically, you know you have many more

0:39:350:39:39

of the lethal, non-trackable objects

0:39:390:39:41

than you do of the trackable fragments

0:39:410:39:44

that are going to break things up.

0:39:440:39:46

So what a precursor should be,

0:39:460:39:48

an indicator that we're getting close to the Kessler Syndrome

0:39:480:39:51

is that we have many more satellites that have anomalies for unknown reasons.

0:39:510:39:55

'It's coming off. Go for deploy.'

0:39:550:39:58

'Oh, roger. Liftoff and the clock is started.'

0:40:010:40:04

This huge satellite was built in Britain in 2002...

0:40:130:40:17

..for the European Space Agency.

0:40:190:40:21

LAUNCH COUNTDOWN IN FRENCH

0:40:240:40:28

It was the largest civilian Earth observation satellite

0:40:320:40:35

ever fired into space.

0:40:350:40:37

And it was very successful.

0:40:380:40:41

But in April 2012...

0:40:430:40:45

..it suddenly stopped working.

0:40:470:40:50

So all of a sudden it went from generating huge amounts of data for scientists down on the ground

0:40:550:41:00

to basically one of the biggest pieces of junk that we see on orbit.

0:41:000:41:03

Some scientists suspect Envisat

0:41:040:41:07

might have been disabled by space junk.

0:41:070:41:10

Sometimes there is no clear indication and it's just a suspicion

0:41:120:41:16

that smaller particles have impacted the satellite and done some damage.

0:41:160:41:20

You can cut a cable easily or you can damage some structural parts.

0:41:200:41:25

So it certainly will happen. And it has happened in space.

0:41:250:41:28

Envisat is now hurtling around the world at over 7km per second,

0:41:320:41:38

in the same orbit as all of the other Earth observational satellites.

0:41:380:41:43

But the much greater threat of a collision with some junk

0:41:460:41:50

was highlighted when scientists built a computer model of its path

0:41:500:41:53

through the largest debris field.

0:41:530:41:55

So what we're seeing here,

0:41:570:41:58

this is the view from Envisat as it's travelling around the Earth.

0:41:580:42:02

These are all the other debris objects that we can currently track from the ground.

0:42:020:42:06

As we're moving along the orbit here,

0:42:060:42:09

what you see is there are plenty of objects that are passing in front of Envisat.

0:42:090:42:15

In some cases, passing right next to Envisat.

0:42:150:42:17

Now, when we get to the poles like this,

0:42:180:42:21

you can see just how crowded the environment actually is.

0:42:210:42:25

And Envisat is just going through that now without any kind of control.

0:42:250:42:28

So there's no way it can manoeuvre to avoid any collision.

0:42:280:42:32

You know, some of these things passing at 14km per second.

0:42:320:42:36

Huge amounts of energy's involved.

0:42:360:42:38

Removing Envisat from its dangerous orbit

0:42:490:42:52

is obviously a pressing problem.

0:42:520:42:54

The satellite company Airbus

0:42:560:42:58

is at the forefront of the race against time

0:42:580:43:01

to bring Envisat back to Earth.

0:43:010:43:04

They build some of the world's most sophisticated and complex satellites

0:43:080:43:13

in their high-tech clean rooms.

0:43:130:43:16

But they're figuring out how to solve the Envisat problem

0:43:160:43:20

in much more humble surroundings...

0:43:200:43:22

..the company's converted bike shed.

0:43:240:43:26

And what they've come up with is deceptively simple.

0:43:280:43:33

They plan to harpoon it.

0:43:400:43:42

This demonstration allows us to prove that we can target a small object,

0:43:430:43:47

a very lightweight object very accurately.

0:43:470:43:51

If we can do that, then we can certainly go and capture very big objects and very heavy objects,

0:43:510:43:57

which is essentially the main targets that we want to capture.

0:43:570:44:01

They hope to launch a chaser satellite,

0:44:100:44:13

which would carefully approach Envisat

0:44:130:44:16

or any other defunct satellite

0:44:160:44:18

and then fire the harpoon.

0:44:180:44:20

So this system will capture those items of debris,

0:44:240:44:29

tow them out of the orbits where they might collide with active satellites

0:44:290:44:35

and allow them to burn up safely in the atmosphere.

0:44:350:44:39

So the idea is to have a system which takes them away from where they cause a problem

0:44:400:44:45

and basically destroy them safely.

0:44:450:44:48

It sounds great in theory,

0:44:540:44:56

but it may not be easy in practice.

0:44:560:44:58

You're firing something, it's going to be travelling pretty quickly.

0:45:010:45:04

It's going to hit the other spacecraft.

0:45:040:45:07

OK? And that's kind of the situation that we're trying to avoid in the first place.

0:45:070:45:10

We're artificially generating a collision here.

0:45:100:45:13

The whole point of this spacecraft,

0:45:130:45:16

of, you know, removing that big junk

0:45:160:45:19

is that we reduce the number of objects that we have on orbit.

0:45:190:45:22

So we don't want to be generating any new debris.

0:45:220:45:25

The harpoon strike could have a much bigger unintended impact.

0:45:320:45:35

Where on that spacecraft are you going to fire your harpoon?

0:45:390:45:42

There are all sorts of things inside there that,

0:45:420:45:44

you know, potentially you can have problems with.

0:45:440:45:47

On the inside of the satellite, we have things like propulsion lines,

0:45:480:45:52

which you can see here, which carry the propellant for the thrusters.

0:45:520:45:56

And electronics boxes and various other bits of equipment.

0:45:560:46:00

So when we punch through this panel,

0:46:000:46:02

we need to take into account that there might be this sort of equipment on the other side.

0:46:020:46:08

Hitting the extremely volatile propellant with a harpoon

0:46:100:46:13

would almost certainly cause an explosion.

0:46:130:46:16

So Dr Jamie Reid and his colleagues

0:46:180:46:20

have been poring over the blueprints of Envisat

0:46:200:46:23

to make sure they can target

0:46:230:46:25

precisely where they want the harpoon to land.

0:46:250:46:28

But there's a final obstacle that might prove insurmountable.

0:46:350:46:40

This is a pretty big spacecraft.

0:46:400:46:43

It needs to be big because we're kind of manhandling this one.

0:46:430:46:46

You know, you're not going to send a mouse to grab an elephant.

0:46:460:46:49

So this spacecraft is big.

0:46:490:46:50

That means it's going to go onto a big rocket.

0:46:500:46:53

And that rocket is going to cost a lot of money.

0:46:530:46:56

So we've invested huge amounts of money into this.

0:46:560:46:58

And its job, essentially, is to grab a bit of junk and then burn it up.

0:46:580:47:03

You know, so it's not really performing any science, anything else.

0:47:030:47:06

That's what its job is for and we're spending huge amounts of money to do that.

0:47:060:47:10

It's certainly true that if you had one satellite

0:47:110:47:14

to go and catch one piece of debris, it would be very inefficient.

0:47:140:47:18

So the advantage of the harpoon design

0:47:180:47:20

is we can have one chaser satellite

0:47:200:47:22

that has lots of different harpoons on it

0:47:220:47:24

and it can go and capture multiple pieces of debris.

0:47:240:47:27

There are other plans to remove defunct satellites,

0:47:410:47:44

including capturing them in a net...

0:47:440:47:47

..sticking a magnetic thruster onto the body...

0:47:490:47:51

..physically grabbing drifting spacecraft...

0:47:530:47:56

..firing a laser beam to change their orbit...

0:47:570:48:00

..and even using solar radiation to sail them off to safety.

0:48:010:48:05

But the debris problem is so huge

0:48:090:48:12

that it might be beyond all of these solutions.

0:48:120:48:15

If I take off a certain number of objects over a certain period of time,

0:48:160:48:19

I'm going to reduce the probability of collision.

0:48:190:48:22

Unfortunately, from the analysis that's been done,

0:48:220:48:25

it's about 35 to 50 removals to prevent one collision.

0:48:250:48:29

That's not great, right?

0:48:310:48:32

A lot of people think, "I remove one object, I've stopped one breakup."

0:48:320:48:36

That is not the way it's going to work.

0:48:360:48:38

It's statistical in nature, it's being very proactive.

0:48:380:48:41

It doesn't mean we shouldn't do it. But it's not one for one.

0:48:410:48:44

It's going to be a huge, huge cost.

0:48:460:48:48

Do we spend the money on removing all these objects?

0:48:480:48:52

Or let's not spend the money.

0:48:520:48:54

Let's leave all the objects in orbit

0:48:540:48:56

and then we take the risk that some of those are going to be hit,

0:48:560:48:59

they're going to generate more fragments

0:48:590:49:01

and we end up in the situation where, you know,

0:49:010:49:04

Earth orbit is completely congested,

0:49:040:49:06

full of fragments and we can't launch new space missions.

0:49:060:49:09

Of course, satellites continue to be launched at about 120 a year.

0:49:170:49:21

But that's not what has scientists most concerned.

0:49:250:49:28

They're worried about these things.

0:49:320:49:35

CubeSats.

0:49:350:49:37

They're far cheaper than your conventional large spacecraft.

0:49:390:49:43

And what that means is we can put up more of these

0:49:430:49:46

and they can perform the kind of space missions

0:49:460:49:48

that we wouldn't be able to contemplate with a larger spacecraft.

0:49:480:49:51

What helps keep the cost down is that they're so small

0:49:540:49:57

they can be launched as part of the payload of a bigger satellite

0:49:570:50:00

or even from the space station.

0:50:000:50:03

They're quite simply thrown into orbit.

0:50:030:50:06

The disadvantage is that they're not manoeuvrable.

0:50:070:50:10

In the end, the problem is similar to a collision, if you like.

0:50:130:50:17

The release event of these objects

0:50:170:50:19

is more or less identical

0:50:190:50:22

to the large release of a cloud of fragments,

0:50:220:50:25

because these CubeSats are not manoeuvrable.

0:50:250:50:28

They cannot avoid collisions.

0:50:280:50:30

Even though the CubeSat is small,

0:50:320:50:35

there's is probably sufficient mass in here

0:50:350:50:37

that if it was to hit a larger spacecraft,

0:50:370:50:40

you know, at 10km per second,

0:50:400:50:43

it would cause a catastrophic breakup of that spacecraft.

0:50:430:50:46

You know, the mass of these could be

0:50:460:50:48

anywhere between 3kg all the way up to 20kg

0:50:480:50:51

and that's enough mass

0:50:510:50:53

to completely destroy a satellite like Envisat.

0:50:530:50:57

Around 100 of these mini satellites were launched in 2014.

0:51:060:51:10

And that number is only set to increase.

0:51:100:51:14

There is no law governing space operations

0:51:200:51:22

and that's primarily because space isn't divided up by national boundaries.

0:51:220:51:27

Space, in the end, is a resource. It needs to be shared globally.

0:51:290:51:33

There is no space above your country that you can reserve.

0:51:330:51:36

Spaceflight happens by orbiting around the full Earth.

0:51:360:51:39

So you have to share the whole space.

0:51:410:51:44

You need to have consensus globally

0:51:440:51:47

on what we do with this precious space.

0:51:470:51:51

Consensus isn't always possible to achieve.

0:52:020:52:07

So the United States, the most powerful spacefaring nation,

0:52:080:52:13

is taking matters into its own hands.

0:52:130:52:16

It's not going to break the bank by investing in unproven technology

0:52:260:52:30

to clean up the debris problem.

0:52:300:52:32

But the Federal Government is spending a billion dollars

0:52:330:52:36

on a new tracking system called Space Fence.

0:52:360:52:40

Space Fence will provide the capability

0:52:460:52:49

to detect, track and catalogue objects

0:52:490:52:52

all the way from the baseball size

0:52:520:52:55

down to sort of marble size,

0:52:550:52:57

depending on the altitude.

0:52:570:52:59

So instead of just tracking 22,000 large objects,

0:53:020:53:06

Space Fence will now allow the Space Surveillance Network

0:53:060:53:09

to track up to 200,000 much smaller objects.

0:53:090:53:14

To be honest, a lot of people would say,

0:53:200:53:23

"Well, let's just put our head in the sand and ignore the problem."

0:53:230:53:26

Well, that's just an irresponsible way to look at the problem.

0:53:260:53:30

If you can see that debris and if you can avoid that debris,

0:53:300:53:32

you need to do everything you can to do that.

0:53:320:53:34

Because every one of those events that is a collision

0:53:340:53:38

creates thousands of other pieces of debris now that you have to track.

0:53:380:53:41

This new system is called Space Fence

0:53:430:53:45

because it produces a fence-like radar beam.

0:53:450:53:48

It's the size of the radar and the huge increase in its frequency

0:53:490:53:53

that allows it to track much smaller objects.

0:53:530:53:57

When an object crosses that fence, we detect it.

0:53:570:54:01

And then we can electronically steer this energy

0:54:010:54:05

so that we can track it very precisely.

0:54:050:54:09

And then once you develop a track on it,

0:54:090:54:13

at that point I can then use physics

0:54:130:54:16

to predict where it's going to be in the future.

0:54:160:54:18

So every time the object goes over the site,

0:54:180:54:22

we would then collect more information on it, more data,

0:54:220:54:25

which allows us to refine the estimate of where it is at,

0:54:250:54:29

again, so that we can predict where it's going to be in the future.

0:54:290:54:31

But there are limitations to this system.

0:54:440:54:46

There are millions of objects of varying sizes orbiting Earth,

0:54:480:54:52

but it's only the thousand or so operational satellites

0:54:520:54:55

that can be moved to avoid a collision.

0:54:550:54:58

So even with the latest technology,

0:55:060:55:10

can science make any worthwhile predictions

0:55:100:55:12

about what might happen in the future?

0:55:120:55:15

What I expect is going to happen is not going to be at all

0:55:150:55:18

what anybody else that you're going to film is going to say.

0:55:180:55:21

Because I don't know what the answer is.

0:55:210:55:23

So I'm just going to tell you you have to live with ambiguity

0:55:230:55:26

and I believe that it will not unfold

0:55:260:55:30

in a predictable, linear, consistent way from anyway that we believe.

0:55:300:55:36

It's going to be sporadic and it's going to be unpredictable

0:55:360:55:40

and we're all going to act surprised

0:55:400:55:43

and myself and Don Kessler and Hugh Lewis are going to go back and go,

0:55:430:55:46

"The variance is large. We told you."

0:55:460:55:49

MALE ASTRONAUT TALKS INDISTINCTLY

0:55:530:55:56

'Right, that looks like it's in there.'

0:55:570:56:00

If Kessler's calculations about the increase in the debris problem are right,

0:56:050:56:10

and so far they have been,

0:56:100:56:12

then scientists forecast that this is what the orbits around Earth

0:56:120:56:15

will look like in the next few centuries.

0:56:150:56:18

'OK, I am ready to receive it.'

0:56:250:56:27

We're using space all the time.

0:56:320:56:35

You know, when we look into the future, that's only going to continue

0:56:350:56:39

and we're going to make more use of space.

0:56:390:56:41

'It did wiggle.

0:56:410:56:43

'To set that to be effective,

0:56:430:56:47

'it needs to be pointed forward.'

0:56:470:56:50

You know, if we are connected via space all the time,

0:56:510:56:54

then space becomes our single point of failure.

0:56:540:56:57

And we've got to tackle that problem.

0:56:570:56:59

But there are also idealistic

0:57:080:57:11

as well as practical reasons

0:57:110:57:13

for wanting to preserve our access

0:57:130:57:15

to what's now one of our most precious resources.

0:57:150:57:20

I want my kids and my kids' kids to be able to explore space.

0:57:250:57:30

And if we ruin the environment, we can't do that.

0:57:300:57:34

And that would be tragic, because my passion for space

0:57:340:57:38

came when I was ten years old and I watched Apollo 11

0:57:380:57:42

and I watched Neil Armstrong walk on the moon

0:57:420:57:44

and that magic that created that feeling in me that said,

0:57:440:57:48

"I want to do space,"

0:57:480:57:50

I want my kids and my kids' kids to have that opportunity.

0:57:500:57:53

And if the space environment is ruined, that will never happen.

0:57:530:57:56

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