Flying Through a ‘Junkyard’: Assessing the Risks of Space Debris
By Andrea Tinning
On March 27, India test-fired an anti-satellite missile to destroy a target satellite flying in low-Earth orbit. Nicknamed “Mission Shakti,” the successful maneuver vaulted India into the ranks of the U.S., China and Russia, the only nations boasting such capabilities. It also drew a rebuke from NASA administrator Jim Bridenstine, who said the debris could risk damaging the International Space Station. India downplayed the dangers. For clarity, Reporting Texas turned to Moriba Jah, associate professor of Aerospace Engineering and Engineering Mechanics at the University of Texas at Austin. Jah and his team created ASTRIAGraph, an autonomous database designed to track satellites and assorted “space junk.” Interview excerpts:
On the controversy:
It’s a he-said-she-said kind of thing. India came out and said they did it but it’s not dangerous. The United States said, “Oh, we measured it and it is dangerous.” The big issue is there’s no globally accessible body of evidence that anybody could tap to come up with their own conclusions. So it can’t be corroborated. You have conflicting viewpoints and nobody has all the evidence. That’s exactly what my research program at UT is trying to remedy.
Risk to the International Space Station:
The fact that [new debris] exists is not good. There’s random junk up there and you can’t predict really when [it] might hit you, so it’s this background hazard that you’ve got to deal with somehow…
There are pieces of debris that are not necessarily in the path of the Space Station, but given that they’re [at] the same altitudes, it could potentially be hazardous.
Why space junk matters:
Any of that stuff could be detrimental to any satellite … and even a human space flight, in the case of the Space Station. Nobody knows exactly where this stuff is, so if you want to fly a satellite, you’ve got to fly through that junkyard. And that’s only the stuff we track … about 1 percent of the stuff that can harm you.
On debris tracking and ASTRIAGraph:
My research group is trying to monitor, quantify and assess the behavior of objects in space and make evidence of these behaviors transparent and accessible to the largest group of people possible …
Anybody who has evidence about something in space can send it my way, we include it, and you can visualize it in a common framework. Given sensor data, it will compute orbits on things autonomously and update the graph database.
On development challenges:
Different people have different opinions on where [debris is located], which is part of the problem. And so, my [process] is, step one: Gather all the evidence. Two: What is all the evidence saying? Three: Wherever there’s inconsistency, figure out why that’s happening. And four: How do you combine all of it to come up with what the best answer should be and how you do that without a human in the loop? How do you get machines to do that stuff?
What can governments do?
Guidelines … have been adopted by the United Nations Committee on Peaceful Uses of Outer Space that talk about the prevention of debris. But they’re only guidelines, they’re not legally binding … The thing governments can do is implement the United Nations’ Long-term Sustainability Guidelines. Governments can basically use that as a legal basis so they can have their own people from their own countries adopt and implement the guidelines. And then a framework like mine should be used to independently monitor and assess … who’s compliant and who’s noncompliant. The only way you can enforce something is if you know about it and you can’t know about it if you don’t measure it.