Let's clean up the space junk orbiting Earth | Natalie Panek

139,916 views ・ 2017-01-05

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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)
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