Has the space junk in Earth orbit really reached a dangerous tipping point?

Space is a vast and often empty place, but within our own orbit, things are getting pretty crowded. There are millions of pieces of debris, from busted satellites to lost chunks of rockets, encircling our planet. Some say it's a deadly menace. But just how dangerous is this space garbage, really?

While space agencies the world over have expressed concern over the growing quantities of junk in Earth's orbit, a recent NASA-sponsored report by the US National Research Council (USNRC) has struck a tone of unprecedented urgency, warning NASA that the levels of space junk surrounding our planet have reached a tipping point. Correction: according to the National Research Council News office, "[The report] did not say that the debris has reached a tipping point, only that some of NASA's models suggest that to be the case."

But not everyone agrees with the tenor of the report. While he acknowledges that the hazards posed by space debris are real, aerospace engineer Hugh Lewis of Southampton University, UK takes issue with the USNRC's publication, saying that Earth's belt of space waste has yet to pose a serious threat:

[The USNRC report] paints quite an alarming picture but I think we can be a bit more upbeat, certainly if we are contemplating removing objects.

Fortunately, space is big and collisions are still very rare. After all, we've only had four known collisions and only one involving two intact objects. It's still not a catastrophic situation, and we need to be careful about using phrases like 'tipping point' and 'exponential growth'.

We've written about promising technologies that could be used to clean up our orbit in the past, but it's important to remember that many of these technologies have yet to move beyond a conceptual stage of development.

While the amount of junk surrounding Earth may not have reached a "tipping point" per se, there is no doubt that levels of debris are, in fact, increasing. Given this, do we really have any business falling back on the fact that "space is big"? After all, the oceans were once considered vast enough to hold our waste here on Earth.

Regardless of your stance on the severity of space debris in its current state, can we all just agree to not screw the pooch on this one? I, for one, would hate to see the progress of projects like deep space exploration impeded by the fact that we can't safely leave our own orbit.

You can read more about the future of our relationship with space debris over at BBC News
The USNRC Report, "Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Programs" is available here
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