Old Soviet satellite breaks apart in orbit after space debris collision

A three-decade-old Soviet satellite has disintegrated in orbit some 870 miles (1,400 kilometers) above Earth, likely following a space debris strike. 

The disintegration of the satellite, either the Kosmos-2143 or Kosmos-2145 spacecraft, was reported on X, previously Twitter, by astrophysicist and space debris expert Jonathan McDowell. The event highlights the precarious situation in Earth's orbit where old objects accumulated throughout the more than 60 years of space exploration and utilization are now posing threats to new, still functioning satellites. 

"Another possible orbital impact event: Seven debris objects cataloged from a defunct Soviet communications satellite launched in 1991," McDowell said in a post on X, previously known as Twitter. "Debris appears to be from either Kosmos-2143 or Kosmos-2145, two of 8 Strela-1M sats launched on the same rocket." 

Old soviet satellites and used rocket stages left at altitudes above 500 miles (800 km) are of great concern to space sustainability researchers. Floating too high to be taken down by the natural decay of their orbits caused by the drag of Earth's residual atmosphere, these objects have already been involved in several incidents. 

Related: How many satellites can we safely fit in Earth orbit?

In February 2009, a cousin of the Kosmos-2143 and Kosmos-2145 spacecraft, a satellite designated as Kosmos 2251, smashed into an operational satellite of the U.S. telecommunications company Iridium 490 miles (789 kilometers) above Earth, creating a giant cloud of space debris. That incident, together with a 2007 Chinese anti-satellite missile test, is responsible for the majority of space junk fragments currently hurtling around Earth. 

In January this year, a dead Soviet spy satellite and a used Soviet rocket stage came within 20 feet (6 meters) of each other in a cluttered region about 600 miles (1,000 km) above Earth. A full-on collision between those two objects would have spawned thousands of new dangerous pieces of debris. 

Researchers don't know and will likely never learn what caused the Kosmos fragmentation reported on Wednesday, Aug. 30, by McDowell. Earth-based radars only track objects larger than 4 inches (10 centimeters). About 34,550 such objects are currently known to exist in Earth's orbits, according to the European Space Agency (ESA). 

But in addition to those "visible" space debris fragments, some 1 million debris objects 0.4 to 4 inches (1 cm to 10 cm) in size and 130 million fragments smaller than 0.4 inches hurtle through space, according to ESA's estimates. When radars register one of the larger objects approaching an operational satellite, operators receive a warning and can move their spacecraft out of harm's way. But there is no warning ahead of the small junk's arrival. 

The problem is that even a space junk fragment as small as 0.4 inches can cause serious damage. In 2016, a space debris fragment only a few millimeters wide punched a 16-inch (40 cm) wide hole into one of the solar panels of Europe's Earth-observing satellite Sentinel 2. The collision spawned several fragments large enough to be tracked from Earth. Sentinel 2 survived the incident, but ESA engineers said that had the space junk hit the craft's main body, the mission could have been over. 

Researchers have been sounding alarm bells for years because of the growing amounts of space junk in Earth's orbit. Some fear the situation is slowly approaching a scenario known as the Kessler Syndrome. Named after retired NASA physicist Donald Kessler, the scenario predicts that the growing number of fragments generated by orbital collisions will eventually make the area around Earth unusable as every space debris crash will trigger a chain of subsequent collisions.