Charting Space Junk

Astrodynamist to lead debris-tracking initiative

Tim Vanderpool, Jacob Chinn photo

It’s no secret that planet Earth has a trash problem. What’s less well-known is the man-made debris orbiting our planet — discarded rocket parts, satellite antennas and other metal scraps hurtling through space at 17,500 mph. These objects are missiles in the making, and a collision could jeopardize everything from GPS satellites to the International Space Station. 

The problem isn’t new. Twenty years ago a French satellite was mangled by debris from a French rocket that had exploded 10 years before that. Yet we still have surprisingly little information about space junk — including how to avoid hitting it. 

Searching for solutions, the UA has brought in Moriba Jah, a spacecraft navigator on multiple NASA missions to Mars who also has assessed space object behavior for the Air Force Research Laboratory. 

The sought-after astrodynamicist has joined the College of Engineering and the Office for Research and Discovery to spearhead the new UA Space Research Initiative. The project, based in the University’s Defense and Security Research Institute, will track the behavior of space debris, flag potential threats and compile usable information for governments and private companies.

The space-junk problem is widespread — and growing. According to Jah, the U.S. Department of Defense tracks approximately 22,000 space objects the size of a softball or larger. NASA tracks even more: over 500,000. “The number of objects has been increasing as more countries get involved in space,” he says, “and there’s been a lot of debris released in the process of putting objects in orbit.” Those objects then collide with each other and disintegrate into even more debris. 

And every piece of junk represents a risk. “Anything with a relative velocity about seven times faster than a speeding bullet — even if it’s one centimeter in size — could pretty much end a satellite mission,” Jah says. Since shooting the objects down is both perilous and pricey, other alternatives are needed.

Many players are motivated to quantify and predict the behavior of objects in space: The Department of Defense wants to protect its military-in-space capabilities. The Federal Aviation Administration is mandated to manage space traffic. The United Nations has a committee on the peaceful use of space and is interested in the long-term sustainability of the space environment.

Reflecting these varied interests, the UA’s research will involve no fewer than six colleges and 11 departments across campus, an interdisciplinary approach that drew Jah to the UA. 

The results will be increasingly critical, given our growing reliance on technology. “Some years ago, the globe didn’t depend on GPS,” Jah says. “Now, if you want to go from Point A to Point B, who pulls out a folding map? Nobody does. Everybody pulls out their smartphone. 

“People think those services are guaranteed. But I have bad news for them: If a couple of those GPS satellites become inoperable, that affects everything from smartphones to global aircraft traffic to navigating the seas. The more the world realizes how dependent we’ve become on these capabilities — and how vulnerable we are — the more interest I believe there will be in finding real solutions.”