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Space Pollution Threatens Low-Earth Orbits


space-debris-orbit-earth.jpg.662x0_q100_crop-scaleCreated by German photographer Michael Najjar, “Space Debris I” is an amazing representation of the satellites, space junk, and everything else currently orbiting Earth. Beautiful, yet frightening, from just one glance it becomes quite obvious that space pollution is already a major problem for national and corporate interests around the globe.

Even after accounting for the proliferation of technology, and acknowledging the importance of satellite communications systems to modern life, the question still begs to be asked, “how could the orbit around earth be so crowded already?”

To many experts, it is known as the Kessler Syndrome. Named after American physicist Donald Kessler, this phenomenon occurs when more and more space junk is added to orbit, increasing the chance for collision and dispersal of shrapnel from the collision. Junk begets junk, and the more junk there is, the greater chance for calamity.

Low-Earth orbits, otherwise known as LEO’s (represented in the rendering as that dense circle smothering Earth) are prime real estate for satellites. Launch rockets can easily make the trip, and the close proximity to Earth offers planet surface scanning in great detail, both for military and civilian purposes. Needless to say, the short distance keeps phone signals stronger than they would have been otherwise.

All of these benefits come with a price though. With a constant orbit, space must be delegated intelligently in order to keep equipment from colliding.

Different from an earthbound collision, a space accident among two or more satellites leads to a wide dispersal of material. In fact, hundreds (or thousands) of pieces of tiny shrapnel (1 cm or more) can have huge negative effects on the movement of traffic in space.

Two interrelated stories show what could result.

In 2007, the Chinese military deliberately destroyed their spacecraft, the Fengyun-1C, during an anti-satellite weapons test, creating an estimated 2,000 pieces of 10cm+ junk, and 35,000 pieces of 1cm+ junk.

Two years later, when the Iridium-33 satellite accidentally collided with a defunct satellite called Cosmos-2251, hundreds of pieces of shrapnel, 10 cm across (and therefore, visible to satellites), were thrown into the orbit.


Both of these situations increased the number of objects in orbit at an altitude of 700km to 1,000km by a full THIRD.

Considering the importance of LEO, this has already fostered a difficult situation, which will only become more obvious as technology becomes more essential to our daily lives.

According to the European Space Agency, the number of collision alerts has doubled in the past decade. According to the European Space Agency (ESA) the number of collision alerts has doubled in the past decade. Nicholas Johnson, the chief scientist for orbital debris at NASA, says modeling of the behavior of space debris “most definitely confirms the effect of the Kessler syndrome”. Even the National Security Space Office at the Pentagon is worrying about whether a tipping-point has been reached, or is coming soon.

Fortunately, learning of the impending problem can help mitigate the adverse effects…to a certain degree. Satellite operation is a global endeavor, meaning we have a great deal of information from many countries about the whereabouts and orbits of their equipment, allowing for strong communication and collaboration to keep accident from occurring. But in reality, knowing when to use fuel reserves to avoid a collision, for example, is only a temporary (and fragile) solution to the greater issue of space gridlock.

Similar to the present course we are taking on earth, the march of progress requires the problem solvers to think very deeply about how we can fix a growing problem that is not going away if left to its own devices.

A few ideas have been thrown out, including the use of ground lasers to change orbits of shrapnel by vaporizing parts of their surface. Ideally, this would create enough thrust to force the debris to re-enter our atmosphere. Another method of “slowing the space junk down” was proposed recently by Alliant Techsystems, who suggested the building of special satellites, encased in several spheres of strong, lightweight materials. When debris hits this surface, it would give up momentum and velocity, eventually falling down to earth.

These are certainly interesting thoughts, but many space agencies are moving towards a “robot mission” alternative. In this scenario, robot-controlled spacecraft’s would make their way into LEO, dock with old satellites and fire rockets to boost them into “graveyard” orbits or send them out of orbit completely.

This makes the military complex nervous though. Knocking out defunct satellites is necessary in keeping LEO a safe thoroughfare, but these ideas make for paranoid Generals who are dedicated to protecting their own from outside threats.

Human nature aside, a solution must be reached. Since we are talking about the vast expanse of space, it is essential (and not unrealistic to assume) that we can create an international effort in order to cooperate and agree upon which objects are removed and where those responsibilities lie.

We already have enough gridlock on earth, so finding technology to either develop a plan of action regarding LEO satellites, or increasing the range of the technology, is not only in the interest of individual nations, but of the entire global community.

Need more motivation? Just watch Gravity

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