Saturday, February 14, 2009

Accident this week highlights how we are making space more hazardous than it needs to be

The astronaut worked carefully, adjusting the solar panel which collected energy for the space station. Space walks were rare nowadays, with sophisticated robots doing most of the routine, and increasingly more complex outside work. But once in awhile there was still a need for a human touch. As she carefully set the final rivet in place, the astronaut felt a sense of exhiliration, not unlike that which anyone would feel upon doing a job better than any robot could....

All of a sudden it happened. A piece of space debris four and a half inches long and perhaps half as wide, weighing about a pound, and probably from some old and forgotten satellite or other relic from the late twentieth or early twenty-first century, ripped through her space suit travelling at several miles per second, many times faster than any bullet that had ever been fired by any gun on the earth. Instantly it passed all the way through her body, and she died in excruciating pain, but very quickly as blood, entrails and other contents of the space suit were ripped out into the icy vacuum of space. The space suit, now useless, shredded as her body blew up in the vacuum and literally exploded.

Even before anything had spilled out, the projectile had shattered the solar panel, depriving the station of power, and smashed into the outside wall. Though the wall had been planned and built extra thick precisely in anticipation of this kind of event, the piece was large enough that it punctured the outer wall. The emergency doors detected the immediate drop in pressure and sealed off the compartment that had been breached, though this meant death for the two astronauts inside it (nothing could be done about that, they almost certainly died nearly as gruesomely as their colleague outside as the air was sucked at an incredible rate through the hole that had been made in the wall.

Science fiction? Perhaps. But this nightmare scenario will be faced by Captain Kirk or any other future astronauts as they venture out into space. It will be confined to the vicinity of earth, but it is our generation's gift to them.

A gift for which we will be cursed probably for hundreds or even thousands of years, just as we today curse those who left such hazards as chemical dumps that continue to poison people who live near them and which we all pay thousands of dollars a year to clean up as those who created them are long since dead, radioactive islands in the Pacific that will not be habitable for thousands of years, or who chose to hunt animals like the passenger pigeon to extinction without giving any thought to what we can't do or see anymore. And remember the tragic episode that happened here in Arizona about a year and a half ago which I blogged about, when a girl lost her life and another was critically injured, courtesy of some now-forgotten miners from a hundred years ago or longer, who simply walked away from the mineshaft they had dug into the earth without bothering to mark it.

Well, now it's our turn to be the miners who don't care what future generations will go through in space as the consequence of our own devil-may-care attitude about it.

As portrayed graphically in this image (though it is a graphic designed to make a point-- the objects are portrayed by scale as miles wide, when they are at most a few meters across), the earth is now being orbited by over 12,000 known pieces of space debris, ranging from fractions of an inch to defunct satellites or pieces of satellites weighing several tons. Pieces now being tracked include such objects as a screwdriver that was once lost on a spacewalk, along with the more mundane such as military, weather or communications satellites that are no longer in use.

But the pieces which are known about and are being tracked are not the ones we have to worry the most about. Rather, it is those which are not being tracked. This problem came into perspective last Thursday when an old Russian military satellite collided with a communications satellite operated by Iridium communications, inc. The fault was clearly that of the Russian government. It is true that most governments don't make the locations of their military satellites public (especially since we know that several nations have the technology to shoot down satellites) but certainly once it was no longer in use the Russians should either have provided tracking data to NASA and other organizations that keep track of this kind of stuff, or else put it into a decaying orbit which would cause it to burn up and fall to earth over water (what is usually done with old satellites.)

God knows how many new, certainly untracked pieces of space junk were created by the collision. Most fell to earth, but many did not and are now orbiting in orbits that no one has a clue about-- until they hit something. Several years ago a tile on the space shuttle was damaged when it apparently hit a fleck of paint-- in other words a tiny piece of orbital debris-- that had apparently flaked off of some long ago space mission. Unneeded trash, human waste (yes, there are shits in space, zipping along hundreds of miles over our head at several miles per second)-- those were once let go into space as well (though to our credit we now recycle everything that can be recycled, and stash the rest.)

Most galling, China test fired a missile several years ago at a real target, a satellite six hundred miles in space. This certainly created thousands of untracked pieces of space debris (well, what do they care? They're China.) Then the U.S. responded with our own missile test last year. The cover story was that we were protecting the population of the earth from lethal hydrazine fuel from a disabled satellite. Of course, even if you found the fuel tank, hydrazine would only be lethal if you stood there and sniffed it for hours (and dozens of satellites with hydrazine fuel tanks have fallen to earth in the past without any consequences.) In other words, it was a missile test to show that we could do what the Chinese can do, but after the flack they took for theirs we had to find an excuse.

Unlike explosions on earth, where nature eventually heals even the most horrific of scars (such as those caused by nuclear testing), an explosion in space is destined to leave debris that will orbit the earth into the far distant future, perhaps forever. It's safe to say that if there is ever a war fought in space then it will turn low earth orbit into a deadly field of orbiting debris that future astronauts will breathe a sigh of relief when they clear. The asteroid belt would probably be a safer place.

Obviously there will always be accidents in space (like dropping a screwdriver) and that can't be helped, but we have an obligation to future generations to begin urging governments and private companies that venture into space to put together a policy by which 1. no dumping of any kind will be allowed (just because we've wised up on this doesn't mean everyone will-- so let's get it in writing while we can and this provision remains relatively non-controversial); 2. all satellites should be tracked or safely removed from near earth orbit (whether that means putting them into a decaying orbit to re-enter over water, as is done now, or whether it means boosting them out of earth's orbit entirely either out of the solar system or into the sun), including military satellites that are no longer in use; and 3. (especially this one) just like the nuclear test ban that the United States and the Soviet Union inked in 1962 when the hazards of atmospheric radiation were becoming obvious and could no longer be ignored, it is time to urge that the U.S., China and any other nation that is developing into space sign a ban against test firing anti-satellite missiles at targets outside of earth's atmosphere (which would in no way prevent any nation from firing a missile not set to explode, into empty space against a virtual target, which a computer could model its motion and indicate whether the missile got there or not.)

But now that we are becoming aware that this is a problem, to do nothing and continue to fill space with thousands of physical hazards and leave it to future generations to fix problems that we could much more easily not cause in the first place, would be the spineless way out.

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