Did you know that due to human activity, there are currently over 100 million debris objects greater than 1 mm in size orbiting the earth? Centimeter- and millimeter-sized orbital debris pose the highest risk to space missions operating in Low Earth Orbit, according to a January 2021 National Science & Technology Council NASA Office of the Inspector General report. A similar January 2021 NASA Office of the Inspector General National Science & Technology Council study report stated that less than 1% of the debris objects that could cause mission-ending damage are currently tracked and debris is insufficiently characterized for risk.
Worse, at orbits hundreds of miles above the earth, debris can potentially stay there for centuries due to lack of atmospheric drag. This means that anything sent up and not brought down (e.g., human-made objects in space that no longer serve a useful purpose) eventually becomes debris.
The number of objects regularly launched into space contribute to this problem. In 2018, Space Exploration Technologies Corporation, or SpaceX, received Federal Communications Commission approval to launch up to 12,000 communication satellites. And in October 2019, the company requested permission to launch an additional 30,000 satellites.
To address this issue, the Intelligence Advanced Research Projects Activity (IARPA) created the Space Debris Identification and Tracking (SINTRA) program, headed by Program Manager, Dr. Alexis Truitt, which aims to persistently detect, track, and characterize small space debris.
“Given the rapid increase in space activity worldwide—both government and commercial—and the current state of orbital debris, small debris tracking is needed to ensure safe equipment and crew operations,” Dr. Truitt said.
Foreign anti-satellite military operations are of particular concern, not only from a national security perspective, but also because of the massive debris fields they create, Dr. Truitt added.
For example, in 2007, China conducted an anti-satellite weapons test on one of its own satellites. That event alone created over 2,000 pieces of trackable debris, and an estimated 100,000 debris pieces overall. Most debris from this weapons test is still in orbit. More recently, in November 2021, Russia launched a ground-based missile and destroyed one of its Cosmos satellites, creating 1,500 pieces of trackable space debris and threatening the safety of crew-members onboard the International Space Station.
The United States condemned these tests, with Vice President Kamala Harris calling them “reckless.”
Although space debris monitoring efforts continue to improve, the inability to detect, track, and characterize 1 mm – 10 cm sized debris remains an issue. The Department of Defense only tracks and monitors debris greater than 10 cm in size using the U.S. Space Surveillance Network.
The National Aeronautics and Space Administration’s Orbital Debris Program Office leads the effort to model the distribution of debris less than 1 mm in size. This model is used to determine how many smaller objects (and their sizes) were in a spacecraft’s flight path. However, because the objects are not tracked, additional objects that drift into the same orbital path could remain undiscovered, potentially resulting in catastrophic damage to spacecraft and life.
To address these gaps, the SINTRA program aims to enhance small debris tracking capabilities by using existing sensors, such as ground-based radar, tracking satellites, and optical sensors, along with emerging research involving measuring plasma waves created by debris. The intent is to identify and track space debris as small as 1 mm, thereby making space missions safer for all countries and industries utilizing earth’s orbit.
The SINTRA test and evaluation team consists of: MIT Lincoln Laboratory, Naval Research Laboratory, Los Alamos National Laboratory, and JHU Applied Physics Laboratory.
“Due to the extent of the space debris problem, SINTRA is critically important for the U.S. government and, frankly, for all nations with space programs,” Dr. Truitt said. “Developing this technology will be a challenge, but it’s one I’m confident we can meet.”
The SINTRA program is anticipated to be a four-year effort.
