In Orbit: How Satellites Rule Our World

'From Mission Director's Center

'at Vandenberg Air Force Base, California,

'this is Delta Launch control...'

Inside that rocket, about to blast off into space, are six satellites.

And they will join thousands of other satellites in orbit

around our planet -

part of the latest technology that we take completely for granted.

But I want to change that.

I want to re-examine

what these masterpieces of engineering are doing for us.

My name is Maggie Aderin-Pocock

and I'm mad about satellites.

In fact, I help make them.

For the last few years,

I've been working on the most ambitious satellite ever...

..the James Webb Space Telescope.

Now, I want to find out how these awe-inspiring machines

have come to fill our skies.

Seeing how 50 years of satellite research

has pushed at the boundaries of technology,

and how this has transformed our world.

'Five, four, three, two,

'main engine start, one, zero.

'And lift off of the Delta 2

'with the NPP satellite.'

This is the story of how satellites

have changed all aspects of our lives

in ways that you can imagine, and many you can't!

It's 6.30am - an average day

in an average house.

But while we sleep, how many of us know

our lives rely on extraordinary machines...

..keeping an eye on us from space?

They influence time,

tuning our clocks.

As I settle down for breakfast,

a satellite beams the signal

to my television.

At least three more make a live link

to the other side of the world.

And a further four

allow the Met Office

to forecast the British weather.

These satellites aren't so surprising.

You probably know about them already.

But what about the hundreds you don't?

Satellites that helped

harvest the wheat

for my husband's cereal,

deliver his milk,

or chose where to grow

the coffee he's spilling.

Others manage our water,

overseeing flood control,

and surges of power

in the National Grid.

Once in my car,

everybody recognises a SAT NAV.

But what about the fuel I use?

My lottery ticket?

Even the train I catch?

All increasingly depend

on satellites.

Trains, planes and automobiles,

shipping, cereals and flooding.

It's not even nine in the morning

and already, I've used nearly 40 satellites.

These are the satellites that have changed our lives.

But what about those that are changing

our understanding of the universe?

This is a full-scale model

of the James Webb Space Telescope.

When the real thing is launched,

around 2018, it'll be

the largest and most powerful

satellite telescope ever built.

With it, we'll be able to see

wider, deeper and more clearly

into space than ever before.

We may even be able to look back to

the very birth of the universe.

For several years, my job has been to work on the special cameras

that will allow the James Webb to peer deep into the cosmos.

By capturing images of stars 13 billion light years away,

it'll look back in time,

helping reveal how the universe itself was created.

I believe the James Webb,

and the countless satellites that dominate our day,

are amongst the great scientific achievements of our age

and sit at the cutting edge of technology.

We're going to look at the breakthroughs

that make this remarkable machine possible.

What were the scientific challenges

that were faced in the satellite revolution?

And in the early days,

there was one problem above all that space scientists wanted to solve -

how do you get something - anything -

to hover in space above the Earth?

Well, a good place to answer that question is here, by this lake.

A beautiful spot to try to launch my own satellite.

Three,

two,

one,

fire!

The force of gravity has, of course,

pulled my wannabe satellite back to Earth.

What goes up always comes down.

Or does it?

As we all know, the Earth is round.

And that means, as we travel over the surface,

it gently curves away from us.

Now, if you can travel fast enough, something miraculous happens -

we keep on falling, but we never hit the ground.

Let's imagine that I can launch this orange at incredible speeds.

It's something Sir Isaac Newton noticed 300 years ago -

relative to something moving horizontally,

the curve of the Earth makes the ground beneath drop away.

If my orange - or anything else - can move fast enough,

it can stay ahead of that curve and effectively outrun gravity.

It'll never fall to Earth.

Because the curvature of the Earth is quite slight,

you need to be travelling at around 8,000 metres per second

to compensate for the pull of the Earth's gravity.

If you can reach this speed,

you're now travelling around the Earth, rather than down towards it.

Not easy, of course, when there's air resistance to slow you down

and obstacles to get in the way.

But once you get above the mountains

and most of the atmosphere -

at, say, 300km up -

you're now in space.

And if you can keep your ball

travelling fast enough,

you can stay ahead of the curve -

you're in orbit.

Well, that's the theory.

But it took 250 years after Newton's death

before anyone built a machine powerful enough

to put it into practice.

In 1957, a Russian rocket carried the first man-made object

into orbit above the Earth.

No bigger than a beach ball, Sputnik stayed in orbit for three months.

For the Soviet Union, it was a massive propaganda victory.

And the beep of its tiny radio transmitter

fired the starting gun for the Space Race.

I've always assumed that as Sputnik was dragged

into a lower and lower orbit,

it got hotter and hotter,

due to the Earth's atmosphere, and was eventually completely burnt up.

But surprisingly, a small piece of that epic space craft is kept here

at the Smithsonian National Air And Space Museum.

So I hear you have a bit of Sputnik actually here on site?

We do, indeed. We have something that is called the firing pin,

which is a relatively small object that is not really a firing pin,

in any sense of the term -

that implies you launch a rocket

by turning a key or something.

But what it really was

was a small metal object

that fit into

the Sputnik space craft,

and when you were ready to start

the system inside that was run by batteries,

you'd pull this out and it would complete the circuit

that would allow the power systems to start to operate.

It's like a toy - sometimes, it has a plastic tag.

Pull it out and the batteries start.

That's essentially what it was.

The firing pin is a tangible reminder

of who won the race into space.

It may be small, but to me, it's a priceless relic

which, by making the connection between the battery and transmitter,

unlocked the age of satellites.

But it wasn't easy.

Desperate to catch up in the Space Race,

it took the Americans years of rocket research...

..and numerous false starts...

..before finally, they successfully launched their first satellite -

Explorer One.

In 1959, Explorer 6 was the first satellite

to take a picture of the Earth.

It doesn't look like much,

but it was enough to get one group of people very, very excited.

Spies!

By the end of the 1950s,

the Cold War was hotting up.

Satellites would allow Soviet and American spies to photograph

each other from a perfect overhead viewpoint.

The Americans quickly launched

the world's first spy satellites -

codenamed Corona.

But now, the spies had to get their film back to Earth.

And their solution was about as bonkers as you can imagine.

They threw them back.

This remarkable footage shows a canister

carrying thousands of metres of used film

being ejected from a Corona spy satellite

200km above the Earth.

18km up, its parachute opens.

Having spent countless millions launching spy satellites,

the Americans now had to catch the results mid-air,

before the Russians could reach them.

This is 037,

one of the planes that attempted

those difficult, dangerous,

and highly secret missions.

Bob Counts clocked 2,000 hours as 037's navigator.

He had the almost impossible task

of spotting the canister falling to Earth,

then plucking it out of the sky

somewhere over the Pacific.

Bob, this is one of the aircraft

that actually caught films from space.

Yes, it's not one of them, it is the very one.

It's one of nine that we had,

but it's the aircraft that caught the first one.

So, what sort of range did the aircraft have?

Its range was 2,000 miles, which was a little bit of a handicap

because we had to operate way at the edge of its endurance

on many of the missions.

Bob and his team were attempting the equivalent

of finding a needle in a falling haystack.

This declassified footage shows

the crew of 037

closing in on their target.

First, the crew suspended a line between two poles

hanging from the back of their plane.

Dangling off it are grappling hooks.

The aircraft would match

its descent rate with the descent of the parachute

and fly in right over the shoot,

like five feet over the shoot,

bringing the parachute between those two poles into this array

of line and grapple hooks.

First time, it's a miss.

Then success! But this was also a remarkable historic first.

This fella here, that's Algene Harmen

and he was in charge of the pole handlers of the recovery crew.

And as they reeled in the capsule, there comes a time

when somebody has to lean out and physically grab it

and bring it on board the airplane.

That was one of his jobs.

And as it came up to the tail,

finally it was close enough,

so he reached out to grab it,

and when he touched it, he jumped back

and let his hands loose because it was hot.

He didn't expect that, coming from the stratosphere.

He thought it was going to be cold,

but he reached back out and got it and brought it on board.

That means he was the first human to ever feel the heat of re-entry.

An unsung hero.

We're all unsung heroes.

144 Corona satellites were launched in all,

taking hundreds of thousands of photographs...

..of Soviet airbases,

bombers,

and rocket launch pads,

as well as Chinese nuclear test sites.

It transformed the American military's understanding

of its Cold War opposition.

But Corona was cancelled shortly after a Soviet submarine

was spotted beneath a mid-air drop zone.

Catching canisters of falling film wasn't just difficult

and dangerous, it was now compromised.

There had to be a better way to get images back from space.

This is a silicon chip.

But not any old chip.

When this device was invented,

it totally revolutionised the world of spy satellites.

It's called a charge-coupled device - a CCD.

At its heart is a thin sheet of silicon

which has an unusual property -

it's sensitive to light.

So if a passing photon hits it,

it takes that photon

and creates an electron,

which can then be stored.

This means it can generate a picture

of anything that's in its field of view.

It changed the rules of the game.

The invention of the CCD in the 1970s allowed satellites

to take pictures, store them electronically,

then transmit them back to Earth

using radio waves.

Today, intelligence agencies don't reveal how powerful

their spy satellites are.

But some details have leaked out.

In 2007, it was revealed US satellites had been targeting

American territory.

In fact, the Superbowl!

US counter-terrorism wanted to monitor potential internal threats.

The real photographs have never been released.

They're just too sensitive.

But it shows the resolution is now powerful enough

to see objects and individuals

down to a few centimetres.

But spying was just the start,

because civilian scientists also began using

this new imaging technology,

transforming our knowledge of the Earth.

It led, of course,

to breakthroughs in our understanding of the weather...

..the shrinking of the icecaps...

..and the effect of cities on our environment...

images that have revealed the full wonder of our planet.

Today, satellite images are everywhere,

and available to anyone at the click of a mouse or the touch of a phone.

It's opened up whole new areas of information and research.

But the sheer mass of data sometimes creates its own challenges.

Dr Albert Lin is using satellite imagery

to explore a remote part of Outer Mongolia.

He's searching for the tomb

of one of history's most infamous leaders -

the Mongol warlord Genghis Khan.

His detailed satellite imagery spans an area

of more than 10,000 square kilometres.

But surveying this virtual landscape is almost as hard

as exploring the real thing.

We're looking at examples, like this, where you've got roads,

you've got rivers, and you've got these features, right?

When you look at it, you say,

each one of these pixels shows me something.

This is the wall of a building. You can tell it's man-made.

You can tell that this is modern.

But there's also this other feature that looks similarly not natural,

it looks strange - like these little dots here,

these mounds there.

They look like they may be something that was made by people.

But they look different than this. And what about them looks different?

It's hard to describe in words. It's hard to quantify.

But something about it looks ancient. It looks more worn down.

I would have picked that out as something of interest at least.

Computers can't recognise the features on a satellite image

that could be ancient ruins.

So all 10,000 square kilometres need examination by human eye.

It's a seemingly impossible task.

But the team's solution is ingenious.

Dr Lin has enlisted the help of thousands of human volunteers.

He's broken the vast satellite images into countless smaller ones,

put them on a website

and invited anyone to join the digital expedition.

If someone sees anything interesting,

they mark it,

and agreement starts to emerge about what's worth exploring.

This is an example of

a lot of human consensus saying,

"I really see something weird there.

"You should go check it out."

Now, let's take a look a little closer.

So we're zooming in again?

Yeah, it looks big, it looks weird, it looks rectangular,

but when you actually look at it in the context

of the other data around it, you see that it's actually

right next to these little dots here.

And when we went out and explored this area, it turns out

those little dots are people's homes.

They're their yurts.

And we found this thing,

it turns out it was actually this ancient fortress.

Now, it might not be the tomb, but it's definitely a clue.

Albert Lin and his volunteer force of armchair explorers

have yet to find Genghis Khan's tomb.

But I find his work a comforting reminder

that even the most powerful technology

can't always better our human judgement.

CCDs have transformed

not only what we take in when we look down at our planet,

but also what we see when we face outwards.

This will be James Webb's task when it's launched in 2018.

It'll be glimpsing galaxies that are almost unimaginably distant -

13 billion light-years away.

How do you capture the intimate detail of a galaxy

spread over millions of light years?

Well, the vital component for the James Webb

is its gigantic golden mirror.

And it's not just size.

To see into the depths of space,

scientists have had to take mirror technology

to a remarkable new level.

One part, above all,

is crucial for the mirrors on space telescopes -

their coating.

This is what does the actual reflecting.

As a space scientist, I've seen many mirrors coated in the past,

but the people who've been given the daunting task of coating

the James Webb mirrors are the technicians here

at Quantum Coatings in New Jersey.

And I'm about to find out how they do it.

The mirrors have to be perfect - the tiniest speck of dust

could be disastrous.

So Quantum's lab

is one of the cleanest rooms in the world,

more spotless even than a hospital operating theatre.

This hexagonal pane of glass is an exact template

of the metal sheets that'll make up the James Webb mirror.

They're made of beryllium - a very rare and extremely strong

and lightweight metal.

That gun has dry ionized nitrogen gas,

he's blowing the surface off.

This is our last chance to blow off any last remaining

particles before it goes into the chamber.

The glass is then carefully placed in a large vacuum chamber.

The mirror's in there, everything's ready to go,

and I've got the pleasure of shutting the door.

For two hours, all the air,

and any remnants of dust,

are extracted from the chamber,

until finally, the gold is added.

Gold is used for the coating

because it reflects infra-red light so well -

the part of the spectrum the James Webb cameras use for imaging.

First, it's heated with a laser, vaporising it.

How much gold are we talking?

The amount of gold we evaporate

is about 40 grams.

The amount that gets onto the mirror is a quarter of that.

Just a few grams.

You must be talking about a fairly thin coating of gold?

To put it into perspective,

one sheet of paper is about one thousandth of an inch thick.

We could fit 100 gold coatings into that piece of paper.

-Into a single piece of paper?

-That's right.

The result - one of the most perfect mirrors on Earth.

So, here we are.

Wow. That is lovely, it's beautiful.

It's so smooth. I've never seen my reflection so clearly.

I think the fantastic thing is the idea

that this coating is going to be out in space... 18 mirrors like this.

-It's quite phenomenal.

-It's quite a thought.

The 18 mirrors are hexagonal

because they fit together more snugly than if curved.

The hexagons also form a shape that is roughly circular,

so focus the light evenly.

These mirrors are typical of the James Webb.

Every aspect of its engineering has been pushed to the limits

of what's technologically possible.

Yet there's a strange irony -

to launch it, we will rely on the same basic technology

that got Sputnik into orbit half a century ago -

a rocket.

With a payload space that's not much bigger.

Yet the James Webb has huge solar panels,

and a sun shield to protect its delicate instruments

that's five layers thick.

It's all very bulky.

So how do you squeeze something as large as this

into a rocket with a carry capacity the size of a school bus?

The answer is origami.

The creator of this miniature theme park is Dr Robert Lang.

And surprisingly, his origami skills have been invaluable

to NASA's space programme.

Because the Japanese art of origami

lets you turn something very large...

..into something very small.

This is the pattern that I just folded.

It's called the Miura-ori and it was discovered by Koryo Miura -

a Japanese engineer working in the Japanese space programme.

He was studying the way thin plates buckle under stress

and that led him to discover this fold pattern.

And he explored it and found it had a really nice property -

it opens and closes with all of the folds happening together

because they're mechanically linked.

Then you would only need to bend a single fold

to make the entire structure open and close.

When you open one fold, all the other folds follow

-and you flatten out.

-Right. So if this were a solar array in space,

-you'd only need to put one solenoid or mechanical...

-Mechanism.

-..mechanism on...

-Yes.

..one fold and that fold would be enough

to make the whole thing open up.

Robert offers to show me how to make something the size of a solar panel

fit it into a small payload bay.

The sheet is nine square metres.

Its transformation will involve

72 separate folds.

Robert pre-creases the folds

to increase accuracy and flexibility.

-Wow, you're forming a spiral.

-Yep.

Origami may be Japanese, but I never expected it be a martial art.

It certainly needs one or two ninja moves.

All right!

So you've taken that huge piece of paper and reduced it to this.

That's right.

So if this had been a solar array,

we've taken it down to the size that could go in a rocket.

Goes up in space, opens up,

and then it's ready to deploy

back to its original flat state.

We've gone down by a factor of just about 100.

About ten in each linear dimension.

And we got that by going from completely flat to a vertical tube.

But much easier to stow in a rocket.

Exactly.

Robert's creation is clever enough.

But the real revelation

comes with its opening.

Although the design appears complex,

because it was folded along one axis,

the whole sunshield can be opened with a single motor.

This animation shows how, in 1995,

Japanese scientists used the same trick to fold a large solar panel

on a satellite called The Space Flight Unit.

It's the brilliant application of 17th-Century Japanese art

to a very modern Western technology.

The ability of satellites to have these large structures

gives them, quite literally,

their most eye-catching feature.

It means we can see them from the Earth.

I can see two flashing things, but I think they're both aeroplanes.

And something else flashing over there.

'I'm with a group of Brownies, trying to spot satellites

'in the early evening sky.'

Now, we don't just look this way, we've got to look all across the sky

and try and take it all in.

I can see the Moon, but I can see two of them.

On average, two satellites pass over Britain

every quarter of an hour.

But they're not the easiest things to see.

Now, what are you looking for?

Well, you're looking for something that looks a bit like an aeroplane,

but won't flash, and it'll move slowly across the sky.

Tonight, my team of Brownies is in for a treat...

..because the biggest satellite of them all

is due to pass directly over Hatfield.

It's the International Space Station,

the largest thing human beings

have ever put into orbit.

It took more than 12 years

and 30 trips to build,

and it circles the Earth nearly 16 times a day.

Everyone - including the astronomers with their telescopes -

is waiting for it to appear over the horizon.

Wow! I can see a star moving really, really quickly!

I don't think that's a star moving - that's a space station.

-I don't see it.

-That is the International Space Station.

There's a crude rule of thumb -

if a satellite orbits 300km up,

it needs to be just one square metre for us to see it with the naked eye.

The ISS has eight solar arrays, each 70m long.

So with a pair of binoculars,

you can see it from Earth in wonderful detail.

What's that?

That's still the space station,

so it's gone all the way from over there,

up above our heads, and now it's heading over there.

Can you see it's still moving slowly...

Like many satellites, the ISS is only visible

for a few minutes before it disappears over the horizon.

-I think it's gone now.

-BROWNIES: Aw!

I know. But at least we saw it.

In the early days of satellites,

this vanishing act was as frustrating

to their engineers and controllers as it was for our Brownies.

It meant that the opportunity to transmit a signal,

like a television picture,

back to a particular point on Earth was very brief.

Maybe only lasting a few minutes.

So the dream of the first satellite engineers

was to have a satellite that stayed stationary

above a single point on the Earth,

allowing them to transmit information whenever they wanted.

So how do you keep an orbiting satellite

hovering above a single point over a rotating planet?

Well, it seems simple -

you just slow your satellite down until it's above the point you want.

But unfortunately, it's a lot harder than it sounds.

And to show you, I'm going to use this carousel.

Imagine it's the Earth, spinning on its axis.

And let's say I'm a satellite, orbiting it.

If I start slowing down to be above just one place,

I'm not going fast enough to stay in orbit,

so I start spiralling down towards the Earth

and eventually, I burn up in the atmosphere.

There is a solution.

The further I get away from the Earth,

the weaker the effect of gravity -

the less it pulls me back.

And there is a magical point where the force of gravity

is so weak that I can travel fast enough to stay in orbit,

but also slowly enough to match the speed of a single point

on the Earth's surface below.

Scientists calculated that this is nearly 36,000km away.

Orbit here and you can stay above the same point on Earth.

You are now in a geo-stationary orbit.

And when this was first achieved, it triggered a revolution,

because now - any time, day or night -

you could beam information back to Earth.

This was the birth of the communications satellite.

It meant that with as few as three geo-stationery satellites,

you could beam a signal

around the planet,

broadcasting it to almost anyone.

The first satellite to relay a television signal was

Telstar in 1962.

Here we are. There's a bar. Now, we are antic...

That's a man's face. There it is! There it is!

Its first broadcast lasted just 19 minutes.

But within a few years,

a network of geo-stationery satellites

meant live communication was possible any time -

or any place - on Earth.

When there are more satellites still,

you'll have television and telephones

all over the globe - a shattering thought.

Broadcast television had created a global living room -

with shared experiences

and values.

Ha-ha-ha-ha!

'25 years of hatred and rage...'

It also meant that as well as recording events,

satellite broadcasts were now helping to cause them.

Like the protests in Tiananmen Square,

the fall of the Berlin Wall...

..or the Arab Spring.

Today, nearly 200 communications satellites

are broadcasting back to Earth.

Most in geostationary orbit.

But staying 35,786km above

a single place on Earth isn't easy.

Satellites tend to drift.

So to keep them in position, you need a technology

that reached its pinnacle with Saturn 5...

..the most powerful rocket ever built.

But rocket thrusters don't all need to be like this.

To keep a satellite like the James Webb in orbit, for instance,

you need thruster technology that's far more precise.

Despite being the size of a tennis court and weighing over six tons,

the James Webb Space Telescope

will use micro-thrusters the size of a coffee cup.

How is this possible?

Well, it's due to the micro-gravity vacuum environment of space.

With virtually no air resistance, or drag,

it can take a tiny force to move a very large object.

Engineers here at the Massachusetts Institute of Technology

are at the cutting edge of thruster engineering,

taking them to a new level of precision.

Here in the lab,

they've got an unusual way of recreating the frictionless

conditions of space.

They're using a table-top and mini-satellites called Spheres.

We have a very smooth surface,

and we also have these air carriages,

which are little structures

we put underneath the satellite that have CO2 attached to them

in these tanks and we use them a lot like an air hockey table.

So, can I see them in action?

Sure, absolutely.

So, your job is going

to be to fly this satellite,

which is sitting right here,

all the way over and dock with this satellite.

I'm not a very good games player, so I'm a bit nervous now.

Let me put this down here.

Twist the controller.

Woo-hoo!

The micro thrusters on the spheres shoot compressed carbon dioxide.

It's colourless, but strips of tinsel show when they're firing.

-So, that would give me some twist?

-Yes. Exactly.

-I could do a dance!

-Yes. Exactly!

Trying to, um... OK.

Now, which way?

OK, that's one of the other hard things to figure out - which way?

As I spin, yeah, I lose my orientation.

Oh, yeah. And it just keeps on going, doesn't it? Uh-oh.

Fire a thruster

and just like in space,

your satellite shoots off in the opposite direction,

with nothing to stop it.

Imagine how hard it is in three dimensions!

So far, they've tested the Spheres on board the ISS.

It shows that their thrusters are so precise,

the Spheres can fly in close formation.

The next step is to build satellites that can do this in open orbit.

There you go. That's a good trajectory.

Now, don't build up too much speed there.

-Hurray!

-Docked!

This ability to keep satellites in one position -

and know where they are - is now remarkably accurate.

But it's had a surprising side-effect,

because it means we can also know our position

extremely accurately.

The story begins back in 1957,

shortly after Sputnik was sent into orbit.

The sound of any object changes as it moves past us.

While Sputnik was orbiting,

American scientists realised they could use this knowledge

to locate it - listening to the changing

sound of its beep as it moved overhead.

It got scientists thinking -

if you could work out the position of a satellite

from here on the ground, could you reverse the process?

Could you use the satellite's known location to find your unknown one?

The result was the Global Positioning System - or GPS...

..and how it works is simpler than you'd think.

It's all due to one of these.

The breakthrough technology that led to GPS was actually a clock.

But not any old ticker. This is an atomic clock,

the most accurate timekeeping device ever built.

For instance, if I set one of these going at the time of the Big Bang

and let it run through,

we would now know the age of the universe to within a few days.

Now, compare that with a Quartz watch

and it would be out by 150,000 years!

Atomic clocks are so crucial to GPS

because the first step in working out your position using a satellite

is to know exactly where the satellite is.

And the best way to do that is using time.

Each GPS satellite broadcasts a signal with a time stamp.

It takes the signal just

a fraction of a second to travel

to your GPS receiver back on Earth.

When it arrives,

the receiver's clock works out how much earlier the signal was sent.

Knowing this time difference means it can then work out

how long it's taken to arrive,

so how far away the satellite is.

But it doesn't do this just for one satellite -

it does it for at least four.

Having calculated how far away each is,

your receiver then creates spheres of distance around you.

And where they intersect is where you are.

There are 31 GPS satellites in all,

and the more you are in contact with,

the more accurate your reading.

It means wherever we are in the world,

GPS can tell us our position within a few metres.

But increasingly, GPS can also tell us what the planet is about to do.

I've come to Japan - to Mount Usu.

It's one of the country's most impressive natural wonders...

..but it's also a time-bomb,

because Usu is a volcano.

In the past, any volcanic activity here

has usually been seen as a false alarm.

The locals tend to ignore it and stay put.

But when, in March 2000,

Usu shook with earth tremors,

scientists insisted 16,000 reluctant locals

were evacuated.

Within days, a huge eruption spewed large amounts

of ash and mud down the volcano,

destroying a hospital, a school, and hundreds of homes.

Yet not a single person died.

The reason scientists were so worried this time

was partly thanks to GPS.

This is one of a network of GPS stations around Usu

that played a key role in saving so many lives.

Over 48 hours,

at the end of March 2000,

the distance between two of these

stations increased by two centimetres.

It doesn't sound much,

but for the volcano experts,

it was a signal

that huge forces were building beneath the surface.

And it helped them decide to order an evacuation.

But, of course, volcanoes aren't the only natural disaster

that's struck Japan...

Last year, the country was devastated by the Tohoku earthquake.

It was one of the worst in the country's history,

triggering a tsunami that reached 40m high.

Nearly 20,000 people lost their lives.

It's hard to believe this was once a school.

Yet despite the fact a GPS receiver stands in the grounds,

on the frontline of the devastation,

GPS technology couldn't predict the earthquake.

Even though GPS can measure

the surface of the Earth in great detail,

it cannot predict tectonic shifts beneath the ground.

It can tell us what has happened, not what's about to happen.

Or that's what we thought.

Professor Kosuke Heki analyses GPS signals,

but he's not working out his location.

He tries to work out why they fluctuate.

He measures how much GPS is disrupted

by electrons in the atmosphere.

It's called the TEC - or Total Electron Content.

Professor Heki has been studying how, after big earthquakes,

rumbling sound waves disrupt GPS signals.

But in the days after the Tohoku earthquake,

he noticed something unexpected.

He discovered a strange disruption in GPS signals

before the earthquake happened.

I want to understand what's happening with this phenomena,

so can you show me a curve of what's happening with no earthquake,

and what's happening if an earthquake is coming?

OK.

So this is the TEC.

TEC?

That's the number of electrons in the ionosphere - about 300km up.

-Yes.

-OK.

This is time.

And if there's no earthquake,

it behaves like a smooth curve, like this.

So why do we get that strange curve? Why isn't it a flat?

Because of the movement of the GPS satellite in the sky.

This apparent movement, apparent change.

So, when it goes through a thick bit of atmosphere,

you get more electrons.

As it's straight overhead, you get fewer electrons, and then again,

-you get a thick bit.

-Yes.

-OK, that makes sense.

-So you get a curve.

But that's if no earthquake's going to happen.

Yes. And if there's earthquake here, for example...

-So that's the earthquake.

-Yes. This is the earthquake.

..then it will leave the normal curve

about one hour before the earthquake - like this.

And there is a disturbance caused by the sound wave.

So it suddenly seems from this curve,

because it's higher than this one,

-you're getting more electrons in the atmosphere.

-That's right.

That seems strange. You've got an earthquake coming

and suddenly, you're getting more electrons in the atmosphere.

Yes, it's a very strange phenomenon.

It's thought that in the lead-up to an earthquake,

forces deep underground somehow energize electrons

high in the atmosphere

which, in turn, disrupts GPS signals.

And Heki has noticed this has also happened

before other earthquakes too,

like Chile in 2010.

It's a remarkable discovery which, at the moment,

scientists don't fully understand.

But it offers hope that one day, GPS will act as an earthquake predictor,

saving countless lives.

For half a century, satellites have been at the cutting

edge of technological advance -

driving rocket design...

..revolutionising how we view the planet...

..transforming our ability to communicate...

..and even to know where we are.

But now, in the early 21st century,

this technology is becoming far simpler and smaller.

Satellites are no longer just for big governments

and powerful corporations. They're becoming almost personal.

And tonight, I've got a front-row seat to discover how.

Here in the Vandenburg Airforce base in California,

scientists are taking the next leap forward in satellite technology.

Inside the tip of the rocket, situated over there,

are some of the first

new prototypes in the personal satellite revolution.

They're called CubeSats, and they look like this.

Five of these satellites will all be released

into orbit hundreds of miles above our heads,

like a flock of strange alien birds circling the earth.

They're owned, mostly, by universities,

and will join the 40 or so other CubeSats

already in orbit.

They do everything - from measuring radiation in the solar system

to studying bacteria in space.

Surprisingly,

one country at the forefront of CubeSat technology is Britain.

Here, engineers have devised

one of the most imaginative uses for them so far.

That bit in the centre is the CubeSat,

but do all CubeSats have these sails as well?

This is a particular mission.

It's called CubeSail.

One of the big hot topics

at the moment is space debris.

There's lots of debris up in space.

So if we can attach these CubeSats to bits of debris -

maybe they be old satellites,

or old parts of launches which are still orbiting up there -

if we can attach these CubeSats to them,

open up the solar sails and allow them

to literally drag them back into orbit

and burn up in a safe manner,

it means we are de-cluttering space.

I must admit,

one of my fears with CubeSats is the idea of all these little things

in space causing more space debris,

but this is actually helping to solve the problem.

-Yes, very much so, indeed.

-It's very neat.

CubeSats all rely on the same basic components,

much like the different parts of a PC.

Here in Surrey, they're taking this to an extreme.

Dr Peter Shaw shows me how they are currently building

a satellite around the smallest and most popular computer

that exists today - the smartphone.

So our modern-day smartphone -

a couple of hundred pounds from the High Street -

is a very capable device.

It's got cameras on there,

it's got storage,

a gigabyte's worth of storage,

it's got processors,

very advanced processors,

it's got accelerometers...

Ah, so the accelerometers are things that orientate the screen,

-so you get a direction?

-Yeah.

That's clever.

And we can use those sensors in our space-craft. OK?

So the whole idea in the future is to get rid of all these components

and replace them with a mobile phone.

So this is the internal structure of the CubeSat itself,

where we'll mount everything on to.

Often, when I think of space science,

you think of huge companies with big budgets,

and although this isn't cheap,

you could almost do it in your garden shed.

Yes, certainly, if you had a bit of money.

Compared to other satellites, for instance,

the big communication satellites,

you're talking 500, 600 million pounds.

If you're talking about satellites the size of a washing machine,

you're talking about 10 to 15 million pounds.

So how much does this cost?

All in all, you could put a whole mission together

for about £80,000.

It seems to me that in the future,

satellites will increasingly provide customised services

for small groups of people - even individuals.

They'll allow imaging,

communication and exploration at a whole new personalised level.

Over the last half-century, satellites have transformed

the way we lead our lives.

But I feel we are now on the launch pad

of a second satellite revolution,

and it's one whose impact could be even more profound.

The age of the personal satellite!

Main engines start... One,

zero and lift-off!

My God! That's amazing. It's so bright, and you can feel it.

You can feel the vibrations.

I've always wanted to see a rocket launch

and to be here and to see it like that...

Just amazing!

That is the fulfilment of a lifetime dream.

Subtitles by Red Bee Media Ltd