“We’ve treated these orbital highways as junk highways”
NASA Johnson: The Milky Way extends above the Earth’s horizon, 2021 (CC)
There are over 8,000 metric tons of leftover rocket bodies, debris, wrenches, and other things like that in various orbital regimes. Some of them [are] concentrated into clusters as well. Next, there are fragments or leftover satellites. They are 10 centimeters and up and can be damaging, even fatal, if they hit an operational satellite. There are about 30,000 such fragments right now. But some [fragments] go down to 1 centimeter, and we don’t have good tracking capability [for them]. There are upwards of 900,000 such pieces and sometimes, they can even go below 1 centimeter. The Aerospace Corporation had a really good comparison of the energy that can be netted from being hit by a 1 centimeter, blueberry-sized object, and it’s like an anvil falling on your satellite. So it’s pretty destructive. And the European Space Agency counts 150 million [fragments less than 1cm]. On top of six decades of this, there are thousands and thousands of satellites that are planning to be launched.
So why does sustainability in space matter? Well, we are embedded in a data society. I was just on an airplane yesterday, and I was pleasantly surprised that my aircraft internet connection allowed streaming services. The end user is just expecting [such services] to always be there, and space helps us do that. Space also plays a major role in national security. We have satellites looking out for missiles as we speak. There are also satellites that provide safety and civil services like weather and GPS, which also affect national security and commercial services. Position navigation timing altogether is massively embedded into our society. It’s also connected to our financial and timing systems, as our most precise timing system is in space, which affects things like ATMs and building access. And then we get into the commercial world. There is about $200 billion purely in commercial services, and so many jobs are reliant on it. So space sustainability is important because we have so much to lose.
So, I think of space sustainability as threefold. It is the environmental piece, the sustainability of our planet as extended into space. [It is also] the economic side of things. If we add too much risk to an environment, we cannot conduct commerce because the cost-benefit analysis will tip the scales. And that is why we need to have supporting logistics to keep this infrastructure clear and operational, just like you have tow trucks running up and down the I-95 to make sure things are clear. And then finally, political sustainability. It is not necessarily the foremost thing you think about when you think of the sustainability of orbits, but this is about public interest and public understanding so that our representatives are well informed and can authorize appropriate government action to sustain GPS and other critical programs for society.