Space Junk

S P A C E :  T H E   F I N A L  J U N K Y A R D

The Race to Contaminate Space* 

 By John Smelcer, PhD

The race for space exploration began with  the  launch of Sputnik  more than half a century ago. All around the world, humanity looked up and marveled at the tiny fleck of light as it raced across the night sky. Nowadays, the marvel seems diminished. Most Americans are unaware of just how many nations (and universities) routinely place objects into orbit. On average, a rocket is shot into space every week. Today, the U. S. Space Surveillance Network, a cooperative project between NASA and the DoD, monitors some 20,000 trackable objects in space, composed primarily of non-functioning satellite components, cables, and rocket parts. But, there are many times more untrackable  objects too small to monitor from Earth. Conservatively, this micro-debris may total more than 500,000 pieces ranging from nuts and bolts to chips of paint, and tens of millions of particles smaller than 1 centimeter in diameter.

space junk 2

(Image depicting orbital pollution 1957-2015)

It was Carl Sagan, the Pulitzer Prize and Emmy Awarding-winning Astronomer (author of the blockbuster movie Contact and host of the hit television series, Cosmos) who raised my awareness of this subject when he once told me over dinner at  a Mongolian Barbeque restaurant in Anchorage, Alaska how callously humanity has carried its terrestrial pollution habits into "The Final Frontier." In 1969, Neil Armstrong walked on the dusty surface of the moon, left his immortal bootprints, said a few magnificent words, and then fired up the lunar landing module and left behind several thousand pounds of spent scrap metal that was only moments earlier useful and expensive scientific equipment. The first landing on another world brought with it the first pollution!

The problem is that spacejunk isn't decomposing as it does in landfills. Instead, these objects are hurling around in their orbits at speeds of 17,500 to 23,000 mph. At such hypervelocity,  even a tiny nut or screw would have far more energy than a rifle bullet.

Add to the scenario over 400,000,000 needle-sized antennas which the Air Force released into space in 1963 as part of a failed Earth-based radio-wave-bouncing experiment. And pieces of metal or paint isn't all that we've left in space. Old rocket fuel tanks slowly leak unignited fuel which, because of zero gravity and extreme cold, produces round globules of jellied fuel which are also racing around our planet occasionally splattering into other objects. Periodically, spectacular explosions result when unspent fuel tank propellant is ignited from collisions. Solid rocket burns in space eject pebble-sized exhaust by-products called "slag."

Astronomers have detected what may be a leftover rocket booster from one of the early Apollo missions on a possible crash course with Earth by 2030. Because of its mass and velocity, should the object, named 2000 SG344, enter our atmosphere, it would release 100 times the energy of the Hiroshima atomic bomb. Is there a real threat? According to Paul Chodas, project engineer at NASA's NEAR Program, the object has the “highest probability of impact that we have ever calculated for an object.”

Like a scene from a James Bond movie, some debris was intentionally created by self-destruction so that sensitive Cold War military equipment wouldn't fall into enemy hands. On occasion, miscalculations in thrust have sent satellites into accidentally-induced high rotation rates where they careen out of their orbits and literally spin apart.

Imagine now a sphere of manmade objects orbiting our planet at between 500 and 1,000 km. Gravity will eventually cause the orbits of these objects to decay thereby sending them into our atmosphere where they will burn up. Unfortunately, the further the orbit, the longer the rate of decay. Orbits below 500 km decay in a year or so; those between 600-1,000 km (or higher) may remain in space for a thousand years.

space junk 3    According to NASA, collisions with space debris occur on almost every mission, and windows on space shuttles have been replaced several times due to hypervelocity micro-impacts. Even Mir,  the former Soviet Union's space station, which burned up in our atmosphere in 2001 (left), had been hit many times, especially on its fragile solar array. The International Space Station is an even larger target. A lethal accident involving accelerated debris  may occur in its active lifetime. Of concern to star gazers, the Hubble Telescope and future orbiting astronomy satellites, including those looking for extra-solar planets, may one day be destroyed by impact.

World space agencies have done little to reduce existing space debris or to decrease future build-up, and none is likely since no one government or organization regulates extraterrestrial development. Most recommendations focus on developing better means of tracking orbital objects and on reducing future debris.

But are there other real considerations of this proliferation of space junk?

Consider, for example, the game of pool. The launch of Sputnik was equal to one ball on an empty pool table. No matter how often you hit the ball, it will not strike another. But add hundreds, even thousands of other balls and you increase the likelihood of collisions exponentially. This is known as a cascade effect.  But this comparison fails to involve the multiple dimensions of space. Unlike the flat pool table surface, objects in space can also come at you from above and below, adding to the chaos. Statistically, the probability that impacts will occur in any particular orbit increases with the square of the number of objects in that orbital region. Scientists already predict that at certain popular orbital altitudes, there may already exist enough debris to begin a cascade, which could create a space environment where little would be safe from collision. An Inter-Agency Space Debris Coordination Commission report theorizes that such a critical mass density  may exist by the year 2040.

space junk 4Since space is seemingly endless, humanity seems to feel that making a junkyard of one tiny, faraway corner of the galaxy is perfectly fine. Consider what we are doing to the Earth today. Already we have turned the oceans into swirling patches of garbage, mostly plastic. Mountainous landfills, a euphemism for what we used to call dumps, are associated with every city. We are a disposable society burying our planet in our refuse. They say 90% of everything we buy each year ends up in the landfill (think of packaging alone). What will be the fate of our planet if we don’t change our ways now? Do we really think we’ll just pack up and move to other faraway planets? And what will we do to those future planets? Will we eventually destroy them by raping their resources and polluting their atmosphere and waterways and burying them in trash? Will we clutter the heavens around those planets as we have ours? Will we forever migrate to the next unspoiled planet only to repeat our follies? Or will we learn from our mistakes? Movies like Disney Pixar’s animated Wall-E are cautionaries about such a disastrous fate. We may be setting into motion events this century which will imprison us on this pale blue planet forever or ruin it for future generations.

*A version of this article was originally published in the May/June 2000 issue of Ad Astra, the official magazine of the National Space Society.

The award-winning author of 60 books, John Smelcer is the inaugural writer-in-residence for The Charter for Compassion, where he teaches a global online course every April called “Poetry for Inspiration and Well-Being.”

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