WEBVTT

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Our lives depend

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on a world we can't see.

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Think about your week so far.

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Have you watched TV, used GPS,

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checked the weather or even ate a meal?

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These many things
that enable our daily lives

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rely either directly or indirectly

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on satellites.

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And while we often take for granted

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the services that satellites provide us,

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the satellites themselves
deserve our attention

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as they are leaving a lasting mark

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on the space they occupy.

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People around the world
rely on satellite infrastructure every day

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for information, entertainment
and to communicate.

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There's agricultural
and environmental monitoring,

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Internet connectivity, navigation.

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Satellites even play a role

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in the operation of our financial
and energy markets.

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But these satellites that we rely on

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day in and day out

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have a finite life.

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They might run out of propellant,

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they could malfunction,

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or they may just naturally
reach the end of their mission life.

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At this point, these satellites
effectively become space junk,

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cluttering the orbital environment.

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So imagine you're driving down the highway
on a beautiful, sunny day

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out running errands.

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You've got your music cranked,

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your windows rolled down,

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with the cool breeze
blowing through your hair.

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Feels nice, right?

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Everything is going smoothly

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until suddenly
your car stutters and stalls

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right in the middle of the highway.

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So now you have no choice
but to abandon your car

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where it is on the highway.

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Maybe you were lucky enough

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to be able to move it out of the way
and into a shoulder lane

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so that it's out of the way
of other traffic.

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A couple of hours ago,

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your car was a useful machine
that you relied on in your everyday life.

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Now, it's a useless hunk of metal

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taking up space in a valuable
transportation network.

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And imagine international roadways
all cluttered with broken down vehicles

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that are just getting in the way
of other traffic.

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And imagine the debris
that would be strewn everywhere

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if a collision actually happened,

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thousands of smaller pieces of debris

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becoming new obstacles.

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This is the paradigm
of the satellite industry.

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Satellites that are no longer working

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are often left to deorbit
over many, many years,

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or only moved out of the way
as a temporary solution.

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And there are no
international laws in space

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to enforce us to clean up after ourselves.

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So the world's first satellite, Sputnik I,

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was launched in 1957,

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and in that year, there were
only a total of three launch attempts.

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Decades later and dozens of countries
from all around the world

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have launched thousands
of more satellites into orbit,

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and the frequency of launches
is only going to increase in the future,

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especially if you consider
things like the possibility

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of 900-plus satellite
constellations being launched.

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Now, we send satellites
to different orbits

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depending on what they're needed for.

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One of the most common places
we send satellites

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is the low Earth orbit,

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possibly to image the surface of Earth

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at up to about 2,000 kilometers altitude.

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Satellites there are naturally buffeted
by Earth's atmosphere,

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so their orbits naturally decay,

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and they'll eventually burn up,

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probably within a couple of decades.

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Another common place we send satellites

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is the geostationary orbit

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at about 35,000 kilometers altitude.

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Satellites there remain in the same place
above Earth as the Earth rotates,

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which enables things like communications
or television broadcast, for example.

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Satellites in high orbits like these
could remain there for centuries.

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And then there's the orbit
coined "the graveyard,"

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the ominous junk or disposal orbits,

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where some satellites
are intentionally placed

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at the end of their life

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so that they're out of the way
of common operational orbits.

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Of the nearly 7,000 satellites
launched since the late 1950s,

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only about one in seven
is currently operational,

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and in addition to the satellites
that are no longer working,

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there's also hundreds of thousands
of marble-sized debris

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and millions of paint chip-sized debris

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that are also orbiting around the Earth.

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Space debris is a major risk
to space missions,

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but also to the satellites
that we rely on each and every day.

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Now, because space debris and junk
has become increasingly worrisome,

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there have been some national
and international efforts

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to develop technical standards

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to help us limit the generation
of additional debris.

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So for example, there are recommendations

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for those low-Earth orbiting spacecraft

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to be made to deorbit in under 25 years,

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but that's still a really long time,

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especially if a satellite
hasn't been working for years.

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There's also mandates
for those dead geostationary spacecraft

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to be moved into a graveyard orbit.

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But neither of these guidelines
is binding under international law,

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and the understanding is that they will be
implemented through national mechanisms.

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These guidelines are also not long-term,

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they're not proactive,

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nor do they address
the debris that's already up there.

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They're only in place
to limit the future creation of debris.

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Space junk is no one's responsibility.

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Now, Mount Everest is actually
an interesting comparison

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of a new approach to how
we interact with our environments,

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as it's often given the dubious honor

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of being the world's highest garbage dump.

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Decades after the first conquest
of the world's highest peak,

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tons of rubbish left behind by climbers

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has started to raise concern,

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and you may have read in the news
that there's speculation

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that Nepal will crack down on mountaineers

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with stricter enforcement
of penalties and legal obligations.

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The goal, of course,
is to persuade climbers

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to clean up after themselves,

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so maybe local not-for-profits will pay
climbers who bring down extra waste,

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or expeditions might organize
voluntary cleanup trips.

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And yet still many climbers feel

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that independent groups
should police themselves.

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There's no simple or easy answer,

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and even well-intentioned
efforts at conservation

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often run into problems.

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But that doesn't mean
we shouldn't do everything in our power

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to protect the environments
that we rely and depend on,

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and like Everest, the remote location
and inadequate infrastructure

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of the orbital environment

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make waste disposal a challenging problem.

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But we simply cannot reach new heights

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and create an even higher garbage dump,

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one that's out of this world.

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The reality of space

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is that if a component
on a satellite breaks down,

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there really are limited
opportunities for repairs,

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and only at great cost.

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But what if we were smarter
about how we designed satellites?

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What if all satellites,

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regardless of what country
they were built in,

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had to be standardized in some way

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for recycling, servicing

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or active deorbiting?

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What if there actually were
international laws with teeth

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that enforced end-of-life
disposal of satellites

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instead of moving them out of the way

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as a temporary solution?

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Or maybe satellite manufacturers
need to be charged a deposit

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to even launch a satellite into orbit,

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and that deposit would only be returned

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if the satellite was disposed of properly

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or if they cleaned up
some quota of debris.

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Or maybe a satellite
needs to have technology on board

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to help accelerate deorbit.

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There are some encouraging signs.

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The UK's TechDemoSat-1,
launched in 2014, for example,

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was designed for end-of-life disposal

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via a small drag sail.

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This works for the satellite
because it's small,

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but satellites that are higher
or in larger orbits

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or are larger altogether,
like the size of school buses,

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will require other disposal options.

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So maybe you get into things
like high-powered lasers

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or tugging using nets or tethers,

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as crazy as those sound in the short term.

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And then one really cool possibility

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is the idea of orbital tow trucks
or space mechanics.

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Imagine if a robotic arm

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on some sort of space tow truck

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could fix the broken components
on a satellite,

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making them usable again.

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Or what if that very same robotic arm

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could refuel the propellant tank
on a spacecraft

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that relies on chemical propulsion

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just like you or I would refuel
the fuel tanks on our cars?

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Robotic repair and maintenance

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could extend the lives of hundreds
of satellites orbiting around the Earth.

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Whatever the disposal
or cleanup options we come up with,

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it's clearly not just a technical problem.

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There's also complex space laws
and politics that we have to sort out.

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Simply put, we haven't found a way
to use space sustainably yet.

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Exploring, innovating
to change the way we live and work

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are what we as humans do,

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and in space exploration,

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we're literally moving
beyond the boundaries of Earth.

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But as we push thresholds
in the name of learning and innovation,

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we must remember that accountability
for our environments never goes away.

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There is without doubt congestion
in the low Earth and geostationary orbits,

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and we cannot keep
launching new satellites

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to replace the ones that have broken down

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without doing something about them first,

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just like we would never
leave a broken down car

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in the middle of the highway.

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Next time you use your phone,

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check the weather or use your GPS,

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think about the satellite technologies
that make those activities possible.

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But also think about the very impact

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that the satellites have
on the environment surrounding Earth,

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and help spread the message
that together we must reduce our impact.

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Earth orbit is breathtakingly beautiful

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and our gateway to exploration.

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It's up to us to keep it that way.

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Thank you.

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(Applause)