Thursday, October 02, 2008

It's Only a Matter of Time

One unfortunate aspect of our quest for technology is our indifference to the vulnerabilities that can come with advances. You probably don't think of it very often but the very functioning of our societies has become dependent on satellites. We're dependent on them for everything from essential communications to global security to weather tracking to navigation and shipping.

As our dependency on satellites has increased, so has their number. The earth is now blanketed by 13,000 of them. Google Earth has produced a brief animation giving you an idea of what this reality looks like.

There's only one snag to all of this and that lies in the mathematical certainty of what is known as the "Cascade." Sooner or later there will be a catastrophic collision between two of these satellites that will generate hundreds or thousands of projectiles that will explosively impact with another satellite and then another and then and increasing number until a critical mass is reached at which the entire satellite web is destroyed.

This isn't a possibility, it's a mathematical certainty. Ask NASA. They know it's a certainty, utterly inevitable, and they know we have no means to prevent it.

Bad as it may be, the loss of our satellites isn't the worst part. The debris field that remains is the greatest problem. It will prevent us from re-establishing satellites for upwards of 60-years. In other words, man will be denied access to space for three generations.

Maybe we'll do better next time.


penlan said...

Wow! That's really interesting. I had no idea. We may end up going back to "print only" for information on anything if this were to happen. I assume this would also affect T.V. to a huge extent?

The Mound of Sound said...

It would wipe out just about all forms of telecommunications as the networks are currently deployed. The loss of the GPS nets would affect commercial navigation. It goes on and on.

It's not considered likely this will begin with a satellite/satellite impact. Far more likely is a chunk of space debris orbiting at 15-25,000 mph exploding a large satellite.

A pea-sized ball bearing at these speeds has the impact of a 400-lb. safe travelling at 60 mph.

At geosynchronous altitudes orbital speeds are much lower - in the vicinity of 500 mph. so impact forces are diminished but there's still plenty of space junk capable of doing the job up there too.

Even the space shuttle runs some risks. NASA has had to change shuttle flight paths at least eight times to avoid debris impacts.

There have been some impacts already, more than 124 have been verified. That's why there is now an estimated debris field totalling 600,000 pieces. And it just keeps growing in size and number of objects. There's the problem.