Sunday, April 5, 2009

The Wall Around the World

A little more than twelve hours ago, the Democratic People's Republic of Korea conducted a missile launch test. The missile lumbered aloft at 11:20 AM local time and was claimed to have successfully deployed its payload into orbit by that Indomitable Bastion of Truth Which Never Ever Lies, the Korean Central News Agency. Most of the world sees this action for what it rightly is, a provocative movement by the last real rogue state. Should North Korea develop an arsenal of ballistic missiles, it would become a far greater threat to its neighbors than it has been in all the years since 1953.

This particular launch was conducted by an Unha carrier rocket, based upon North Korea's existing Taepodong-2 ballistic missile, and for which there have been no complete flight tests. Considering that it took SpaceX four tries to smooth out all the rough edges on their Falcon 1 rocket, it's hardly a surprise that the rocket and its payload, supposedly the Kwangmyongsong-2 communications satellite, failed to achieve orbit and crashed into the Pacific.

Nevertheless, as world leaders react to Kim Jong-Il's latest defiant gesture, the issue continues to be framed in what I can't help but classify as a twentieth century mode of thinking. It's all being framed as the necessary prevention of North Korea developing a ballistic missile system that would further magnify the threat of its nuclear arsenal. Nuclear proliferation does remain a major issue, but unlike the days of the Cold War I do not believe that it is the most serious issue that faces us today - honestly, I would be surprised if it was in the top five.

The spread of rocketry to more and more organizations has the potential to make possible a new threat to the world which, while no less dangerous than the spectre of nuclear proliferation, would be far more subtle, incredibly difficult to reverse, and is hardly recognized as a danger by a majority of the world in the first place. I didn't want to write about this until the launch had been completed, because my nagging fear was that the North Koreans were not attempting to launch a communications satellite, but trigger the Kessler Syndrome.

The problem with orbit is that nothing really goes away. Until an object dips low enough to burn up in the atmosphere, it will remain wheeling around Earth at orbital velocity, whether it is a functioning satellite or a discarded wrench or even something as innocuous as a lost screw. The problem arises when these objects collide with one another. Orbital velocity carries incredible kinetic energy, and it would not take much of an impact to reduce a satellite to shrapnel.

There are enough satellites in orbit right now that, if left alone, many of their orbits would certainly intersect, resulting in the destruction of both and the generation of huge quantities of debris zipping through Low Earth Orbit on new paths of their own, new paths which would undoubtedly send them crashing into yet more satellites. If we are ever to go into space in a serious way, active removal of this orbital debris will be an absolute necessity. Otherwise this cascade of satellite debris destroying satellites and creating yet more debris could easily lead to the generation of a cloud of debris saturating Low Earth Orbit, rendering spaceflight effectively impossible for decades or generations.

That would be bad enough. The problem is that this is a situation which can conceivably be husbanded by knowing hands. Imagine, if you will, that the North Korean rocket managed to deliver its payload into orbit. Then imagine that the payload was not a communications satellite as KCNA claimed, but instead a thousand or so ball bearings. These ball bearings would be sprayed out every which way, wheeling around in individual orbits, a thousand whiffs of grapeshot to shred the satellite system.

It's easy to forget about the way space works because so much of it runs counter to the expectations of those who've never left Earth. Space is effectively eternal, and low orbit has a long memory. If we're to make it out of the twenty-first century with any health and strength at all, it's incumbent upon all of us to recognize the dangers of the Kessler Syndrome, and to take action to ensure that low orbit is not allowed to become a wall around the world.

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