MORGANTOWN, W. Va. — The rapidly growing “space economy” is on pace to reach one trillion dollars over the next decade. However, a researcher at West Virginia University says all of that satellite technology is under constant threat from floating space debris.
Piyush Mehta, an assistant professor of mechanical and aerospace engineering, says navigation, weather, and communication satellites are becoming a bigger part of daily life every year. Also circling our planet are roughly two million pieces of old space debris, according to NASA. Making matters worse for the extremely expensive satellites society now relies on is the fact that many share the same low Earth orbit with this potentially hazardous junk.
Specifically, low Earth orbit refers to anything circling the plant between 124 and 621 miles above the ground.
“In low Earth orbit, our ability to safeguard these space assets depends on modeling of the aerodynamic forces acting on the satellites, specifically satellite drag. The drag force acting on a satellite is affected by various physical parameters, however, the most crucial and uncertain are the drag coefficient and mass density,” Mehta says in a university release.
The danger comes down to drag and mass
Mehta says the relationship between drag coefficient and mass density typically sees scientists holding one of these factors constant (often drag coefficient) while examining the other. However, the researcher notes this results in inconsistencies and errors when it comes to understanding the changes in mass density between the upper atmosphere or thermosphere. For monitoring decaying satellites, scientists need precise figures which calculate where a satellite is heading — and what it might crash in to.
Thanks to a grant from the National Science Foundation — the Faculty Early Career Development Award — Mehta plans to examine the threat from Earth’s space junk population in greater detail.
“We will achieve this by not assuming the drag coefficient to be a constant but gaining statistical insights into the physical process that drives changes in drag coefficient, specifically the gas-surface interactions that describe the way energy and momentum are exchanged between the atmosphere and the satellite.” Mehta explains. “The CAREER Award will alleviate this inconsistency through an innovative methodology that combines artificial intelligence and statistical estimation techniques. This is a very niche domain with only a handful of research groups around the world tackling the problem.”
“Dr. Mehta’s cross-cutting research lies at the intersection of atmospheric sciences, space systems engineering and machine learning,” adds Jason Gross, associate professor and interim chair of mechanical and aerospace engineering, and associate chair for research at the Statler College. “With the continued rapid increase of manmade satellites in low Earth orbit, his work toward improved orbital decay prediction becomes more important for the future of space environment sustainability with each passing day. His lab is at the forefront of this important field, and we are proud that he is on our faculty.”