A near-disastrous collision almost occurred
A near-miss collision almost occurred in Earth’s orbit (Image: Getty).
On September 22, LeoLabs, a company specializing in satellite tracking and orbital objects, detected a dangerous near-miss collision between two large objects in low Earth orbit.
LeoLabs identified one object as Cosmos 807, a 400 kg payload launched by the Soviet Union in 1976. The other object was the Chang Zheng 4C rocket stage from China, weighing approximately 2,000 kg, launched five years ago.
Both objects were moving at a speed of about 7.5 km/s and came within 36 meters of each other, with a collision probability of 0.1%, or one in a thousand.
Experts at LeoLabs believe that, given the speed and size of these objects, an accident could pose a threat to astronauts on the International Space Station (ISS) or China’s Tiangong Space Station if it were to occur.
The energy from a potential collision would also generate around 3,000 pieces of debris in low Earth orbit, creating significant hazards for future space missions.
A recent report by the European Space Agency (ESA) noted that, despite ongoing efforts to minimize space debris, thousands of fragments currently in orbit continue to pose risks to space missions.
In June 2021, space debris even pierced the robotic arm of the International Space Station. Prior to that, in February 2009, a defunct Russian spacecraft collided with an operational American Iridium communications satellite.
The collision resulted in the destruction of both spacecraft and created over 2,300 pieces of large space debris.
How much space debris is there?
According to ESA, humans have launched approximately 12,170 satellites since 1957, with 7,630 still in orbit today, but only about 4,700 of them remain operational.
This means that nearly 3,000 non-functional satellites continue to orbit Earth at breakneck speeds, along with large and hazardous fragments like rocket upper stages.
A NASA report estimates that there are at least 26,000 pieces of space debris the size of a softball or larger orbiting Earth—large enough to destroy a satellite.
Over 500,000 pieces of debris the size of a marble pose the potential to damage spacecraft, while more than 100 million smaller fragments could puncture space suits.
Spacecraft have also collided with each other in orbit. The most notable incident occurred in February 2009 when Russia’s defunct Kosmos 2251 satellite collided with the operational Iridium 33 communications satellite, resulting in nearly 2,000 pieces of debris larger than a softball.
Operators often opt for disposal when a satellite reaches the end of its operational life rather than spending additional funds to move it into a “safe zone.” Consequently, space debris continues to accumulate in vast quantities in Earth’s orbit.