A motor from a Russian rocket exploded in orbit earlier this month, the US Space Force has confirmed.
The explosion and subsequent break up of SL-12 R/B (#32398, 2007-065F), as the Space Force enumerated the object, generated 16 new pieces of space debris that the Space Force is now tracking.
Unlike Russia’s intentional use of an anti-satellite missile to destory an old Soviet space satellite in November, the rocket motor explosion on 15 April was unintentional.
The missile test generated a cloud of debris that temporarily threatened the International Space Station and forced astronauts and Russian cosmonauts to take shelter in spacecraft docked to the space station for a possible emergency return to Earth.
The rocket motor in question was a Russian SOZ “ullage” motor in orbit since its rocket launched three satellites in 2007, according to Jonathan McDowell, a Havard astrophysicist who also tracks satellites and space debris in his spare time.
In a series of Tweets, Dr McDowell explained that the motor was part of a Blok DM type upper stage to a Proton rocket, which used two of the motors to place payloads into orbit. He also noted the oenological origins of the term “ullage.”
Russian SOZ motors don’t use all of their propellant during launch, Dr McDowell added, so they often explode years later. At least 54 SOZ are known to have exploded, generating 173 pieces of orbital debtis he said, while another 64 of them remain in orbit.
Space debris is an increasing problem, and one compounded by the rapidly increasing number of satellites in orbit, which increases the likelihood that debris will smash into a satellite, generating more debris.
If enough such collisions take place, they can initiate a runaway chain reaction known as the Kessler Syndrome, similar to the chain reaction that destroys satellites in the film Gravity, and which would eventually render space inaccessible.
Unlike the film, however, a real world Kessler Syndrome would take decades to play out, a slow moving ecological disaster that would prevent humans from exploring space for years to come.