Enchanting graph shows unpleasant close encounters between space debris

As the number of satellites and space debris in orbit around the earth continues to increase, so does the chance that these man-made objects collide with each other, possibly creating more debris that could threaten other healthy spacecraft. Now a new tool shows how busy the Earth's orbit is through space objects by following their short calls every few seconds.


Called the "Conjunction Streaming Service Demo", ”The graphical tool illustrates in real time the huge number of space objects – from an assortment of 1500 items in a low orbit around the earth – that come uncomfortably close together in a 20-minute period. While the X-axis keeps track of time, the Y-axis shows the short distance between two approaching space objects, ranging from five kilometers to the dreaded zero kilometers. The graph shows a series of arches that show when two pieces of rubble move together quickly, approach their approach closest and then drive off.

It doesn't matter when you look at the tool, there is always an abundance of arcs in the graph. If the curve is extremely stretched, two objects have just had an extra close call. And some get frighteningly close within minutes. At the time I was writing this story, the closest thing was that two objects came together just 60 meters. Each arc also has a color code that indicates which types of objects are approaching each other. Green arcs indicate two operational satellites that could potentially separate; yellow arches indicate a movable satellite and a non-maneuverable object; red arches indicate two dead objects that have no other choice than to continue on their possible crash course. There are many red bows in my graph.

The visualization is the creation of Moriba Jah, an associate professor at the University of Texas, who specializes in tracing orbital waste. He said the purpose of the tool is to show that objects always bump into each other, despite the enormous space around the earth. "Things cross each other at very high speeds," Jah says The edgeand notes that some of these objects move 15 times the speed of a bullet. “These things travel very, very fast and certainly come close together. People need to be aware of that. "

The visualization of Jah is based on orbital data collected by the US Air Force, which is responsible for maintaining a comprehensive catalog of the space objects circulating around the Earth. He noted that the graph only displays predictions based on that data and that the positions of the objects may differ slightly. It is also important to remember that while these things to be coming close, most of these satellites are relatively small. "This is why there are no real collisions," says Jah. "Although things come within (a few hundred) meters, the actual size of the objects is much, much smaller."

To prevent potential collisions in space, the Air Force will warn satellite operators if their spacecraft bumps into something and give a notification when the chance of a collision is high. If possible, operators will put their satellites out of the way to prevent a possible impact. It is a process that always happens, usually without much fanfare. And now satellite collisions in space are extremely rare. The most striking orbit crash occurred in 2009 when an Iridium communication satellite collided with a dead Russian satellite.

But that one collision illustrated what is at stake when satellites get close. The accident created thousands of pieces of rubble in orbit, which subsequently posed their own threats to other functioning spacecraft.


Experts are concerned that such incidents will occur more frequently in the future. There are currently around 2,000 operational satellites orbiting the Earth and more than 22,000 pieces of rubble are being actively followed by the US Air Force. However, the number of satellites in a low orbit around the Earth will increase significantly, especially as private companies such as SpaceX, OneWeb and Amazon promise to fill the Earth's orbit with thousands of spacecraft to send internet coverage to the planet below. One of SpaceX's satellites came too close to a satellite from the European Space Agency, forcing European officials to drive their vehicles out of the way.

A study by NASA estimated that practically all satellites in these mega constellations must be safely removed from the orbit every five years, otherwise the risk of collisions will increase exponentially. With Jah & # 39; s tool it is clear that even now a low earth orbit is full, which means that the management of all incoming space traffic will be crucial if we want to keep the space clean.

"It should not be interpreted as" Wow, look at all these collisions. "No," says Jah. “But look how close these things come. And that traffic will only increase. So it comes down to the absolute risk of a collision with that increased traffic coming close together. "

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