Joshua Cohen is a Principal at Fat Pencil Studio
What do you think are the top threats to our way of life in 2021? A global pandemic? Climate change? Political violence? I’m guessing orbital space junk did not make your short list… but it should.
Before I was a designer in the legal profession, I had a career in the space industry. So I knew about the growing amount of man-made debris accumulating in Earth orbit. At the time (early 1990’s) the problem did not seem very urgent. After all, the very name, “space junk” seems to imply that there is plenty of space up there to go around. It turns out that this assumption is a classic tragedy of the commons mistake.
Fast forward 25 years, and many of the things we use every day rely on satellites. This is a bigger deal than you might think. Global Positioning System (GPS) satellites were originally designed for navigation, to guide the movement of military assets. However, over time the precise timing signals broadcast by GPS satellites became critical to the smooth operation of the global computer networks that run our telecommunication, power, transportation, and financial networks. We’ve got a lot riding on having 24 operational GPS satellites in orbit at all times. There are a few spares, so losing one satellite wouldn’t be the end of the world, but losing a bunch at once could screw things up in ways that would make the Covid pandemic disruption seem tame by comparison.
One way to understand the space junk problem is to think about your experience as an airline passenger. What you see looking out the window is open air, and rarely another plane. It doesn’t seem very congested, but in fact there are thousands of planes flying at all times, and they converge on a relatively small number of important destinations: airports. So we have air traffic control to prevent mid-air collisions, and for the most part, this works because we can both track and control the movement of every single plane.
Now imagine you are a passenger on the space station, traveling at nearly 5 miles per second (10x faster than a bullet). Looking out the window you’ll see lots of empty space, and yet there are about 3,000 active satellites, 6,000 inactive satellites, and 20,000 other objects (debris) large enough to be tracked by US Space Command. When objects collide in orbit (this has happened) the result is explosive fragmentation. To avoid having astronauts turned into space junk, NASA Mission Control adjusts the orbit of the space station when necessary to avoid close calls with tracked objects. This used to be an infrequent occurrence, but is now happening about once a month.
Unfortunately, most active satellites aren’t nearly as maneuverable as the space station, while inactive satellites and orbital debris can’t be controlled at all. Plus there are over one million objects in orbit (i.e. bolts, bits of plastic, flecks of paint) that are too small to track but could disable a satellite on impact. And don’t get me started on countries that have tested anti-satellite weapons, creating huge amounts of new debris when targets are destroyed. This all adds up to a problem that cannot be solved by the space equivalent of air traffic control.
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This AstriaGraph view shows active and inactive satellites only, omitting space debris
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When space debris is added, things get a lot more crowded
Experts believe we are in danger of experiencing Kessler’s Syndrome, where increasingly frequent collisions create so much space junk that certain orbits could become unusable. One possible solution is to enact strict design guidelines to allow for in-orbit servicing, and end-of-mission disposal for all satellites. However, there is no legal requirement to do this in the United States, not to mention the dozens of other countries currently building and launching satellites. Even if there was a law or treaty in place, there’s no guarantee that people would follow the rules, if they don’t believe that space junk is a problem.
Luckily, Moriba Jah and his team at UT Austin Center for Space Research have created a free web-based simulation called AstriaGraph that provides real-time 3d views of every trackable object in Earth orbit. You can even click to learn more details about individual satellites. Curious to see where the recently launched batch of SpaceX Starlink satellites are right now? You can find them using AstriaGraph. Orbital analysis software has existed for many years, but it has always been expensive or complicated— useful for aerospace engineers but not the general public. AstriaGraph is simple to understand, easy to load on any computer or mobile device, and visually striking.
I’ve known for years about the space junk problem “in theory” for years, but seeing the sheer magnitude of objects in AstriaGraph gave me a new understanding of the problem and a sense of urgency to share the story with others. If the number of news stories I’m seeing on the subject is any indication, AstriaGraph has sparked broad public interest, that I hope will drive policy changes in the near future.
To learn more:
- In this 8 minute video, Moriba Jah uses AstriaGraph to share his insight on Space Junk issues with Loren Grush, a reporter for The Verge.
- There are now private companies working with satellite insurers to place a value on clean orbits, and deliver tools to help achieve this objective. One such company, AstroScale just launched a mission called ELSA-d to demonstrate magnetic docking technology that could be used to de-orbit inactive satellites or space junk. If done carefully they might even be able to orchestrate spectacular light shows such as the one caused by a Falcon 9 rocket upper stage burning through the upper atmosphere over Portland and Seattle last week:
- SpaceX intends to build and launch a constellation of 12,000 active Starlink satellites to provide internet service from Low Earth Orbit. The latest batch of 60 was launched on March 23rd bringing the total number of Starlink spacecraft launched by SpaceX to 1,385.
- For a real deep dive, check out the 2021 Space Horizons conference. Charity Weeden of Astroscale spoke on Monday Feb 8th (@ 59:30 in discussion video) and Moriba Jah spoke on Wednesday Feb 10th (@ 4:45 in discussion video). Links to these discussion videos are at the bottom of the main conference page.