WASHINGTON — SRI International announced Oct. 4 it selected the defense technology firm Leidos and startup Scout Space as subcontractors for a space debris-tracking project funded by the U.S. intelligence community. 

SRI, a nonprofit research institute based in Menlo Park, California, is one of four companies that won contracts from the Intelligence Advanced Research Projects Activity to attempt to track tiny debris objects in orbit that currently are undetectable by ground-based sensors. 

The project, known as Space Debris Identification and Tracking (SINTRA), is expected to be completed in four years. IARPA is an agency under the Office of the Director of National Intelligence.

IARPA wants to identify technologies and methods to successfully track debris objects smaller than 10 centimeters long, or about the size of a credit card.

“Small debris is an unaddressed and growing threat,” said Lin van Nieuwstadt, a senior engineer at SRI and principal investigator. Even objects as small as paint chips can cause serious damage to spacecraft. 

‘A difficult problem’

As much as scientists have worked on this issue for decades, “it is such a difficult problem to look at the small objects,” van Nieuwstadt told SpaceNews

SRI will experiment with new approaches to analyze radar data in order to hone in on the smallest debris objects in low Earth orbit, she said. “We hope to extend reliable tracking of objects in space down to previously unobservable scales.” 

SRI has extensive experience using radar to track space objects, van Nieuwstadt noted. The company LeoLabs, which operates a global network of radar sensors to monitor low Earth orbit, was founded in 2016 in Menlo Park by former SRI International executives.

For the SINTRA project, SRI will not be working with LeoLabs. It will use data from a radar site the company manages for the National Science Foundation at Poker Flat in Alaska, and from other ground-based sensors.

The company plans to study data from multiple radar instruments to see how radar signals already being beamed into space from large transmitter antennas could incidentally bounce off small space debris and return to receiver antennas. SRI operates a steerable radio telescope at Stanford University that would serve as the receiver.

‘Improve the algorithm’ 

Once the team starts collecting data, said van Nieuwstadt, “we’ll improve the algorithm to make it finer” so smaller objects can be identified. “That’s the secret sauce that we’re trying to come up with.”

To collect data in orbit, SRI will work with Scout Space, a startup based in Alexandria, Virginia, that is developing spaceborne sensors.

Sergio Gallucci, Scout’s chief technology officer, said the company is developing a payload that would support the SINTRA project as well as other programs. 

“Part of our effort is ensuring interoperability with a variety of potential hosts to facilitate future deployments of our payloads for space debris sensing,” he said in a statement to SpaceNews

Scout plans to launch its payload in the near future, he said. “It may contribute to in-space debris tracking under this program, but we are primarily supporting design, processing, and exploitation of solutions.”

Leidos, based in Reston, Virginia, will do plasma modeling for the SINTRA project. 

This will help investigate a type of signature, or plasma waves, created by debris as they fly through plasma in the upper regions of Earth’s atmosphere and in radiation clouds farther out in space. The idea is to try to detect the plasma waves using existing sensor technology. 

“These plasma signatures might have been previously overlooked because we weren’t looking for them, not realizing their potential usefulness,” said Tony van Eyken, director of the Center for GeoSpace Studies at SRI and co-principal investigator.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...