0:00:00.800,0:00:02.256
Our lives depend

0:00:02.280,0:00:04.040
on a world we can't see.

0:00:04.920,0:00:06.936
Think about your week so far.

0:00:06.960,0:00:10.176
Have you watched TV, used GPS,

0:00:10.200,0:00:13.160
checked the weather or even ate a meal?

0:00:13.720,0:00:16.416
These many things[br]that enable our daily lives

0:00:16.440,0:00:19.296
rely either directly or indirectly

0:00:19.320,0:00:21.016
on satellites.

0:00:21.040,0:00:22.976
And while we often take for granted

0:00:23.000,0:00:25.536
the services that satellites provide us,

0:00:25.560,0:00:28.376
the satellites themselves[br]deserve our attention

0:00:28.400,0:00:30.376
as they are leaving a lasting mark

0:00:30.400,0:00:32.119
on the space they occupy.

0:00:32.720,0:00:36.336
People around the world[br]rely on satellite infrastructure every day

0:00:36.360,0:00:40.416
for information, entertainment[br]and to communicate.

0:00:40.440,0:00:43.296
There's agricultural[br]and environmental monitoring,

0:00:43.320,0:00:46.376
Internet connectivity, navigation.

0:00:46.400,0:00:48.096
Satellites even play a role

0:00:48.120,0:00:51.600
in the operation of our financial[br]and energy markets.

0:00:52.120,0:00:54.016
But these satellites that we rely on

0:00:54.040,0:00:55.696
day in and day out

0:00:55.720,0:00:57.376
have a finite life.

0:00:57.400,0:00:59.296
They might run out of propellant,

0:00:59.320,0:01:00.856
they could malfunction,

0:01:00.880,0:01:04.575
or they may just naturally[br]reach the end of their mission life.

0:01:04.599,0:01:08.736
At this point, these satellites[br]effectively become space junk,

0:01:08.760,0:01:11.080
cluttering the orbital environment.

0:01:11.840,0:01:15.456
So imagine you're driving down the highway[br]on a beautiful, sunny day

0:01:15.480,0:01:16.896
out running errands.

0:01:16.920,0:01:18.576
You've got your music cranked,

0:01:18.600,0:01:20.056
your windows rolled down,

0:01:20.080,0:01:22.776
with the cool breeze[br]blowing through your hair.

0:01:22.800,0:01:24.000
Feels nice, right?

0:01:24.640,0:01:27.016
Everything is going smoothly

0:01:27.040,0:01:29.696
until suddenly[br]your car stutters and stalls

0:01:29.720,0:01:31.560
right in the middle of the highway.

0:01:32.160,0:01:35.456
So now you have no choice[br]but to abandon your car

0:01:35.480,0:01:36.920
where it is on the highway.

0:01:38.200,0:01:39.536
Maybe you were lucky enough

0:01:39.560,0:01:42.456
to be able to move it out of the way[br]and into a shoulder lane

0:01:42.480,0:01:44.616
so that it's out of the way[br]of other traffic.

0:01:44.640,0:01:45.896
A couple of hours ago,

0:01:45.920,0:01:50.400
your car was a useful machine[br]that you relied on in your everyday life.

0:01:51.000,0:01:53.536
Now, it's a useless hunk of metal

0:01:53.560,0:01:57.240
taking up space in a valuable[br]transportation network.

0:01:57.920,0:02:02.096
And imagine international roadways[br]all cluttered with broken down vehicles

0:02:02.120,0:02:04.976
that are just getting in the way[br]of other traffic.

0:02:05.000,0:02:07.896
And imagine the debris[br]that would be strewn everywhere

0:02:07.920,0:02:10.376
if a collision actually happened,

0:02:10.400,0:02:12.776
thousands of smaller pieces of debris

0:02:12.800,0:02:14.720
becoming new obstacles.

0:02:15.680,0:02:19.256
This is the paradigm[br]of the satellite industry.

0:02:19.280,0:02:21.416
Satellites that are no longer working

0:02:21.440,0:02:25.256
are often left to deorbit[br]over many, many years,

0:02:25.280,0:02:28.816
or only moved out of the way[br]as a temporary solution.

0:02:28.840,0:02:31.096
And there are no[br]international laws in space

0:02:31.120,0:02:33.760
to enforce us to clean up after ourselves.

0:02:34.680,0:02:36.936
So the world's first satellite, Sputnik I,

0:02:36.960,0:02:39.216
was launched in 1957,

0:02:39.240,0:02:42.880
and in that year, there were[br]only a total of three launch attempts.

0:02:43.520,0:02:47.056
Decades later and dozens of countries[br]from all around the world

0:02:47.080,0:02:50.456
have launched thousands[br]of more satellites into orbit,

0:02:50.480,0:02:54.216
and the frequency of launches[br]is only going to increase in the future,

0:02:54.240,0:02:56.816
especially if you consider[br]things like the possibility

0:02:56.840,0:03:00.440
of 900-plus satellite[br]constellations being launched.

0:03:01.560,0:03:03.616
Now, we send satellites[br]to different orbits

0:03:03.640,0:03:05.696
depending on what they're needed for.

0:03:05.720,0:03:08.056
One of the most common places[br]we send satellites

0:03:08.080,0:03:09.656
is the low Earth orbit,

0:03:09.680,0:03:11.656
possibly to image the surface of Earth

0:03:11.680,0:03:14.080
at up to about 2,000 kilometers altitude.

0:03:14.720,0:03:18.176
Satellites there are naturally buffeted[br]by Earth's atmosphere,

0:03:18.200,0:03:20.136
so their orbits naturally decay,

0:03:20.160,0:03:21.696
and they'll eventually burn up,

0:03:21.720,0:03:23.680
probably within a couple of decades.

0:03:24.440,0:03:26.536
Another common place we send satellites

0:03:26.560,0:03:28.216
is the geostationary orbit

0:03:28.240,0:03:30.840
at about 35,000 kilometers altitude.

0:03:31.320,0:03:35.496
Satellites there remain in the same place[br]above Earth as the Earth rotates,

0:03:35.520,0:03:39.800
which enables things like communications[br]or television broadcast, for example.

0:03:40.440,0:03:44.760
Satellites in high orbits like these[br]could remain there for centuries.

0:03:45.960,0:03:49.136
And then there's the orbit[br]coined "the graveyard,"

0:03:49.160,0:03:51.776
the ominous junk or disposal orbits,

0:03:51.800,0:03:54.656
where some satellites[br]are intentionally placed

0:03:54.680,0:03:55.896
at the end of their life

0:03:55.920,0:03:59.680
so that they're out of the way[br]of common operational orbits.

0:04:00.800,0:04:05.376
Of the nearly 7,000 satellites[br]launched since the late 1950s,

0:04:05.400,0:04:08.760
only about one in seven[br]is currently operational,

0:04:09.360,0:04:12.256
and in addition to the satellites[br]that are no longer working,

0:04:12.280,0:04:15.776
there's also hundreds of thousands[br]of marble-sized debris

0:04:15.800,0:04:18.216
and millions of paint chip-sized debris

0:04:18.240,0:04:20.240
that are also orbiting around the Earth.

0:04:20.880,0:04:23.656
Space debris is a major risk[br]to space missions,

0:04:23.680,0:04:27.680
but also to the satellites[br]that we rely on each and every day.

0:04:28.520,0:04:31.936
Now, because space debris and junk[br]has become increasingly worrisome,

0:04:31.960,0:04:34.576
there have been some national[br]and international efforts

0:04:34.600,0:04:36.096
to develop technical standards

0:04:36.120,0:04:39.040
to help us limit the generation[br]of additional debris.

0:04:39.480,0:04:41.736
So for example, there are recommendations

0:04:41.760,0:04:43.856
for those low-Earth orbiting spacecraft

0:04:43.880,0:04:47.296
to be made to deorbit in under 25 years,

0:04:47.320,0:04:49.416
but that's still a really long time,

0:04:49.440,0:04:52.760
especially if a satellite[br]hasn't been working for years.

0:04:53.320,0:04:56.376
There's also mandates[br]for those dead geostationary spacecraft

0:04:56.400,0:04:58.640
to be moved into a graveyard orbit.

0:04:59.480,0:05:03.176
But neither of these guidelines[br]is binding under international law,

0:05:03.200,0:05:07.976
and the understanding is that they will be[br]implemented through national mechanisms.

0:05:08.000,0:05:10.456
These guidelines are also not long-term,

0:05:10.480,0:05:11.896
they're not proactive,

0:05:11.920,0:05:15.256
nor do they address[br]the debris that's already up there.

0:05:15.280,0:05:19.120
They're only in place[br]to limit the future creation of debris.

0:05:19.680,0:05:22.840
Space junk is no one's responsibility.

0:05:23.680,0:05:26.536
Now, Mount Everest is actually[br]an interesting comparison

0:05:26.560,0:05:29.776
of a new approach to how[br]we interact with our environments,

0:05:29.800,0:05:32.096
as it's often given the dubious honor

0:05:32.120,0:05:35.120
of being the world's highest garbage dump.

0:05:36.040,0:05:39.296
Decades after the first conquest[br]of the world's highest peak,

0:05:39.320,0:05:41.576
tons of rubbish left behind by climbers

0:05:41.600,0:05:43.536
has started to raise concern,

0:05:43.560,0:05:46.296
and you may have read in the news[br]that there's speculation

0:05:46.320,0:05:48.376
that Nepal will crack down on mountaineers

0:05:48.400,0:05:51.960
with stricter enforcement[br]of penalties and legal obligations.

0:05:52.600,0:05:55.016
The goal, of course,[br]is to persuade climbers

0:05:55.040,0:05:57.216
to clean up after themselves,

0:05:57.240,0:06:02.136
so maybe local not-for-profits will pay[br]climbers who bring down extra waste,

0:06:02.160,0:06:05.640
or expeditions might organize[br]voluntary cleanup trips.

0:06:06.120,0:06:08.376
And yet still many climbers feel

0:06:08.400,0:06:11.640
that independent groups[br]should police themselves.

0:06:12.120,0:06:14.936
There's no simple or easy answer,

0:06:14.960,0:06:18.016
and even well-intentioned[br]efforts at conservation

0:06:18.040,0:06:19.880
often run into problems.

0:06:20.320,0:06:23.416
But that doesn't mean[br]we shouldn't do everything in our power

0:06:23.440,0:06:26.760
to protect the environments[br]that we rely and depend on,

0:06:27.440,0:06:31.456
and like Everest, the remote location[br]and inadequate infrastructure

0:06:31.480,0:06:32.896
of the orbital environment

0:06:32.920,0:06:35.280
make waste disposal a challenging problem.

0:06:35.920,0:06:38.456
But we simply cannot reach new heights

0:06:38.480,0:06:41.536
and create an even higher garbage dump,

0:06:41.560,0:06:43.720
one that's out of this world.

0:06:45.280,0:06:46.496
The reality of space

0:06:46.520,0:06:49.096
is that if a component[br]on a satellite breaks down,

0:06:49.120,0:06:52.016
there really are limited[br]opportunities for repairs,

0:06:52.040,0:06:54.080
and only at great cost.

0:06:54.760,0:06:58.256
But what if we were smarter[br]about how we designed satellites?

0:06:58.280,0:06:59.576
What if all satellites,

0:06:59.600,0:07:01.896
regardless of what country[br]they were built in,

0:07:01.920,0:07:03.816
had to be standardized in some way

0:07:03.840,0:07:06.376
for recycling, servicing

0:07:06.400,0:07:07.880
or active deorbiting?

0:07:08.560,0:07:12.096
What if there actually were[br]international laws with teeth

0:07:12.120,0:07:14.896
that enforced end-of-life[br]disposal of satellites

0:07:14.920,0:07:17.056
instead of moving them out of the way

0:07:17.080,0:07:18.680
as a temporary solution?

0:07:19.560,0:07:22.496
Or maybe satellite manufacturers[br]need to be charged a deposit

0:07:22.520,0:07:24.816
to even launch a satellite into orbit,

0:07:24.840,0:07:27.296
and that deposit would only be returned

0:07:27.320,0:07:29.856
if the satellite was disposed of properly

0:07:29.880,0:07:32.600
or if they cleaned up[br]some quota of debris.

0:07:33.440,0:07:36.016
Or maybe a satellite[br]needs to have technology on board

0:07:36.040,0:07:37.800
to help accelerate deorbit.

0:07:38.720,0:07:40.976
There are some encouraging signs.

0:07:41.000,0:07:45.696
The UK's TechDemoSat-1,[br]launched in 2014, for example,

0:07:45.720,0:07:47.656
was designed for end-of-life disposal

0:07:47.680,0:07:49.616
via a small drag sail.

0:07:49.640,0:07:52.216
This works for the satellite[br]because it's small,

0:07:52.240,0:07:55.936
but satellites that are higher[br]or in larger orbits

0:07:55.960,0:07:58.816
or are larger altogether,[br]like the size of school buses,

0:07:58.840,0:08:01.256
will require other disposal options.

0:08:01.280,0:08:04.256
So maybe you get into things[br]like high-powered lasers

0:08:04.280,0:08:06.096
or tugging using nets or tethers,

0:08:06.120,0:08:08.440
as crazy as those sound in the short term.

0:08:09.160,0:08:11.056
And then one really cool possibility

0:08:11.080,0:08:14.400
is the idea of orbital tow trucks[br]or space mechanics.

0:08:14.840,0:08:16.456
Imagine if a robotic arm

0:08:16.480,0:08:18.336
on some sort of space tow truck

0:08:18.360,0:08:20.656
could fix the broken components[br]on a satellite,

0:08:20.680,0:08:22.520
making them usable again.

0:08:23.240,0:08:25.176
Or what if that very same robotic arm

0:08:25.200,0:08:27.536
could refuel the propellant tank[br]on a spacecraft

0:08:27.560,0:08:29.536
that relies on chemical propulsion

0:08:29.560,0:08:33.039
just like you or I would refuel[br]the fuel tanks on our cars?

0:08:33.559,0:08:35.216
Robotic repair and maintenance

0:08:35.240,0:08:38.960
could extend the lives of hundreds[br]of satellites orbiting around the Earth.

0:08:40.280,0:08:43.176
Whatever the disposal[br]or cleanup options we come up with,

0:08:43.200,0:08:46.176
it's clearly not just a technical problem.

0:08:46.200,0:08:51.256
There's also complex space laws[br]and politics that we have to sort out.

0:08:51.280,0:08:55.440
Simply put, we haven't found a way[br]to use space sustainably yet.

0:08:56.720,0:08:59.616
Exploring, innovating[br]to change the way we live and work

0:08:59.640,0:09:01.616
are what we as humans do,

0:09:01.640,0:09:03.136
and in space exploration,

0:09:03.160,0:09:06.416
we're literally moving[br]beyond the boundaries of Earth.

0:09:06.440,0:09:10.096
But as we push thresholds[br]in the name of learning and innovation,

0:09:10.120,0:09:15.600
we must remember that accountability[br]for our environments never goes away.

0:09:16.520,0:09:20.696
There is without doubt congestion[br]in the low Earth and geostationary orbits,

0:09:20.720,0:09:23.056
and we cannot keep[br]launching new satellites

0:09:23.080,0:09:25.376
to replace the ones that have broken down

0:09:25.400,0:09:27.456
without doing something about them first,

0:09:27.480,0:09:29.936
just like we would never[br]leave a broken down car

0:09:29.960,0:09:31.360
in the middle of the highway.

0:09:31.760,0:09:33.336
Next time you use your phone,

0:09:33.360,0:09:35.856
check the weather or use your GPS,

0:09:35.880,0:09:40.136
think about the satellite technologies[br]that make those activities possible.

0:09:40.160,0:09:42.016
But also think about the very impact

0:09:42.040,0:09:45.336
that the satellites have[br]on the environment surrounding Earth,

0:09:45.360,0:09:50.056
and help spread the message[br]that together we must reduce our impact.

0:09:50.080,0:09:52.616
Earth orbit is breathtakingly beautiful

0:09:52.640,0:09:55.216
and our gateway to exploration.

0:09:55.240,0:09:57.760
It's up to us to keep it that way.

0:09:59.160,0:10:00.376
Thank you.

0:10:00.400,0:10:02.480
(Applause)