An outdated Russian engine has exploded in space, producing 16 more potentially hazardous fragments.
Since the 2007 launch of the GLONASS satellites, the Russian SOZ ullage motor (also known as ullage rockets) has been in orbit for 15 years. The motors are used to assist in placing payloads, in this instance a Russian satellite navigation system, into the desired orbit. In Zero-G, fuel may drift away from its intended location, particularly when a vessel slows its acceleration.
The ullage motors are responsible for gently accelerating the whole spacecraft, pumping fuel back into the tanks in preparation for the main engines to resume in orbit. Without it, spacecraft or probes might get stuck as the fuel drifts away from where it is required.
Despite their usefulness, they are not devoid of issues.
"The SOZ motors don't use up all their propellant when they fire. And they have an unfortunate tendency to go bang years or decades later, leaving a bunch of debris in a highly elliptical orbit," Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics wrote on Twitter. "At least 54 SOZ motors have now exploded."
The latest explosion, revealed on Tuesday through Twitter by the 18th Space Defense Squadron of the U.S. Space Force, caused the rocket to shatter into at least 16 pieces, which are now being monitored. This engine will likely reenter the Earth's atmosphere, but it might take years or decades.
"173 debris objects from those explosions are currently being tracked, but the true number is probably a lot higher because tracking is less complete for high orbits," McDowell added.
It is fair to conclude that space is becoming more cluttered with debris. The potential for debris to produce the Kessler Effect is a worry (or Kessler Syndrome).
Simply explained, the Kessler Effect occurs when a single incident (such as a satellite explosion) in low-Earth orbit causes a chain reaction in which debris kills neighboring satellites.
If this were to occur, the junk may continue to collide with other satellites and debris, perhaps creating communication issues and rendering some regions of orbit inaccessible to spacecraft. Similar to the film Gravity, but with less George Clooney and more "hey, where's my GPS?" Some think that, at worst, it may effectively lock humanity on Earth, preventing us from leaving.
Reference(s): ScientificAmerican.