Small Satellites Could Be Playing a Dangerous Game of Bumper Cars in Space

Image: NASA
Image: NASA

Space is full of all sorts of garbage that can cause problems, including some of the stuff we send up there with good intentions. Take CubeSats. These nanosatellites, which weigh less than three pounds, were first sent into space in December 2006, and have become increasingly popular in the years since as a cost-effective option for telecommunications companies looking to spread wifi and brand recognition. The thing is, there are so many of them now that experts are concerned about them bashing into each other—or worse.


This week at the European Space Agency’s conference on space debris in Darmstadt, Germany, Hugh Lewis, a senior lecturer in Aerospace Engineering at the University of Southampton, detailed how catastrophic it could be for satellites should one rogue CubeSat crash into another and another. In the worst case, this could trigger a collisional cascade known as the Kessler Syndrome, which manifests as a terrifying cloud of space junk that would pose significant risk to working spacecraft, including the ISS. Haven’t you seen Gravity?

New Scientist reports that Lewis and his team “have used a supercomputer to simulate 200 years of possible orbits for 300 different megaconstellation scenarios,” or sprawling networks of CubeSats. Apparently, these vast networks of small satellites increase the risk of a catastrophic collision leading to destruction of a satellite by 50 percent.

Helpfully, the ESA also released a 12-minute documentary on space junk today, detailing the threat posed not just by CubeSats, but by the hundreds of thousands of smaller pieces of garbage flying around Earth’s backyard.

Lewis and his fellow researchers have recommended that space agencies like the ESA bring down inactive satellites sooner to prevent the space junk situation from spiraling out of control. They’ve also encouraged redesigning small satellites so they can steer clear of objects and suicide plunge into Earth’s orbit once their lifespan has ended.

Of all the ways to usher in worldwide panic, if the cause is tiny fucking satellites, I’m gonna be so pissed.

[New Scientist]


Space Writer, Gizmodo


To what? I mean, they could increase the risk 50,000 percent and still not be a danger at all if the numbers are small enough to begin with.

Let’s do some simple math to get an idea of what we’re talking about.

Cubesats are delivered to Low Earth Orbit which can range from 160Km to 2000Km in altitude. That’s a volume of space measuring roughly 1.292 x 10^21 cubic meters* or 1.292 million million million cubic meters.

If we deployed a million cubesats into LEO they would each be separated by millions of cubic meters of empty space. Currently there are not even 2,000 cubesats deployed. The risk of a collision must be vanishingly small, even if we assumed 100% of those sats were in the same orbits. Increasing that risk by 50% is probably negligible at worst.

Or my math is totally wrong. Someone back me up or tell me why I’m wrong.

* Earth is a sphere with a radius of roughly 6,378Km, so if we add 2,000Km we get a sphere of 2.463 x 10^21 cubic meters. Then we subtract 1.171 x 10^21 cubic meters (a sphere of 6,378Km plus 160Km for the lowest earth orbit) to find the space between 160Km and 2,000Km of altitude.