The long view and the space debris problem

I listened to a lecture on orbital space debris recently and it got me thinking about how we view the world. First a little background on space debris. At the beginning of the space age when we started putting satellites into orbit around Earth, everyone subscribed to the “Big Sky” theory. It goes something like this: space is huge, satellites are tiny, so the chance of them running into each other is negligibly small and not worth worrying about. It was true to a point, space is huge. Consider the 420 km altitude orbit of the ISS. If we think of that orbit as a sphere with radius 6798 km (Earth radius is an average of 6378 km), then that orbit “sphere” has a surface area of 580,727,222 square kilometers, and the ISS is approximately 7900 square km. So the ISS occupies 0.0014% of its orbit area at any time, not much huh.

Fast forward a few decades and we now have thousands of orbiting objects moving over our heads, about 12,000 that we can track. These are things bigger than 10 cm, about the size of a baseball. It turns out only a small fraction of those objects are useful satellites, less than 4% of that 12,000. The rest are dead satellites, pieces of rockets, broken components, paint chips, etc. Anything smaller than 10 cm we can’t see them at all, but they can still hit with tremendous force. Rifle bullets travel around 1-2 km/s, objects in Earth orbit travels around 7-8 km/s! You do not want to get hit by that. Unfortunately there are an estimated 500,000 untrackable small objects in orbit. So it’s like mine field up there.

In 1978, Donald Kessler at NASA proposed what is now known as the Kessler Syndrome. It states when you have a bunch of moving objects in an enclosed space, like Earth orbit, eventually two of them will collide with each other turning two pieces into many more pieces. Then those pieces can cause further collisions. Over time, the rate of collisions will increase until there is nothing left but a cloud of broken parts that makes satellite operation impossible. It would be like driving into a hail of bullets, moving a 7 km/s! Dr. Kessler came up with the theory from studying how rings form around planets.

Back then, no one thought it would be a problem, but a few years ago we had a wake up call. In 2009, an Iridium satellite and Kosmos satellite collided in space and destroyed each other. The event created 1875 trackable objects and 60,000-120,000 small untrackable objects. The collision has “polluted” that orbit, making it dangerous to put anything else there. Looking forward, the projections say in 100 or 200 years if we continue business as usually, low Earth orbit will become unusable and full of trash (remember the movie Wall-E?). The solution to this problem? Making sure all future satellites and their operators are responsible neighbors and get rid of their retired satellites. However to do that, we all have to take the long view of the consequences of not complying. That means thinking about  what we leave our grandchildren and their children instead of what will directly benefit us this week or next year.

Unfortunately, human life spans are short, and wealth and political power are even shorter. If I will only live another 50 or 60 years, why should I bother with something that won’t become an issue for 100 or 200 years. For politicians or CEOs the timelines are even shorter. A Senator, Representative, President, or CEO will be in office for maybe a decade. Space debris, and space in general are not hot topics these days in the political arena. For companies, the profit margin for this year or next year if likely more important than space debris that may not happen for 100 years. But this is a irresponsible way to view the world. Your decisions today may not affect you, but it may affect your children, or their children. Life continues after you are gone, the world continues. Taking the long view improves the lives of everyone and makes you a better steward of the Earth that is our home. I rarely refer to Bible verses, but it is curious to know even God wish us to take care of our home (Ezekeil 34:2-4, Isaiah 24:4-6). So take the long view.


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