In a heart-stopping moment for space safety, NASA’s TIMED spacecraft and the defunct Russian Cosmos 2221 satellite narrowly avoided a collision above Earth. The incident has raised concerns about the growing risks of space debris and the need for improved monitoring and mitigation strategies.
The near miss occurred at approximately 1:30 a.m. ET on Wednesday when the two satellites passed within a mere 66 feet (20 meters) of each other some 378 miles (608 kilometers) above Earth. LeoLabs, a California-based company specializing in tracking and analyzing objects in Low Earth Orbit, reported the incident. Given the high speed at which these objects travel, over 17,500 miles per hour (28,165 kilometers per hour), the proximity was “too close for comfort.”
The two satellites involved were NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics Mission (TIMED) spacecraft, launched in 2001 to study the Sun and Earth’s upper atmosphere, and the Russian Cosmos 2221, a defunct defense satellite launched in 1992. Both satellites lack maneuverability, leaving ground observers unable to intervene.
LeoLabs, which monitors over 20,000 objects in Low Earth Orbit using phased array radars worldwide, estimated that the satellites likely passed within 20 meters of each other. A collision between the two would have resulted in “significant debris generation,” increasing the risk of further collisions in a wide area of Low Earth Orbit, particularly affecting satellite constellations and crewed space missions.
LeoLabs further analyzed the potential impact of a collision, suggesting it could have generated approximately 2,000 to 7,000 trackable fragments. This incident could have potentially increased the number of fragments in Low Earth Orbit by 50%. Currently, there are around 12,000 fragments in Low Earth Orbit.
Near-misses like this are rare, with only six events in the past two years featuring a miss distance of less than 66 feet between two intact, non-maneuverable objects. This incident highlights the growing concerns over space debris and the urgent need for improved monitoring and mitigation strategies to ensure the safety of current and future space missions.
According to Darren McKnight, LeoLabs’ senior technical fellow, some altitude regions in Low Earth Orbit are worse than others, with half of the population in Low Earth Orbit comprised of fragments and massive derelict objects. Large derelict objects represent just 12% of the total number in space but account for 45% of the total mass. Collisions between these large objects can create thousands of fragments, escalating the risk of further impacts. McKnight emphasized the importance of space traffic coordination processes and technologies to ensure the long-term safe operations of constellations of small satellites.
The only previous satellite collision on record occurred in 2009 when Iridium 33, a U.S. communications satellite, and Kosmos-2251, a defunct Russian military satellite, collided in orbit above Siberia. This event produced more than 1,800 pieces of debris larger than 3.9 inches (10 centimeters), making it the most severe accidental fragmentation on record.
Fortunately, incidents like this should decrease over time due to newly implemented rules from the Federal Communications Commission. These rules require satellite providers to retire their satellites within five years of completing their missions, reducing the risk of space debris and potential collisions.
As we continue to explore space and rely more on satellites for various purposes, it is crucial that we prioritize space safety and take proactive measures to mitigate the risks associated with space debris. Improved monitoring systems and regulations are necessary to ensure the long-term sustainability of space activities and protect our valuable assets in orbit.
