Debris from a Russian anti-satellite missile is causing chaos in orbit, with shards of ex-spacecraft circling the Earth at perilous speeds.
Dan Oltrogge, chief scientist at space operations biz COMSPOC, explained how space junk generated from anti-satellite weapons (ASAT) are a “pressing threat to security and sustainability” at a talk during this week’s annual Small Satellite Conference in Utah.
Debris from the 2021 destruction of Cosmos 1408, a 2,200kg offline signals intelligence satellite, has caused an uptick of close approaches – also known as “conjunction squalls” – with active spacecraft and satellites being launched into space.
“Conjunction squalls represent a step change in the number of conjunctions that a satellite or family of satellites experience with a fragmentation debris source,” Oltrogge told The Register.
“A common manner of formation is that a fragmentation event occurs that pollutes an orbital plane, and this plane later becomes coplanar with an active satellite constellation’s orbital plane.”
There have been hundreds of thousands of conjunctions with the Russian ASAT debris, he said. SpaceX’s Starlink satellites have experienced over 6,000 close approaches, where some form of space junk has come within 10km, SpaceNews first reported. Out of those events about 1,700 were involved with ASAT debris, Oltrogge told us.
Conjunction squalls don’t just affect Starlink birds, however. The space junk affects the majority of spacecraft in Sun-synchronous orbit, according to research [PDF] led by COMSPOC. The International Space Station, for example, is at risk of colliding with ASAT litter. Over time, the debris particles will gradually disperse and fall due to orbital decay.
To prevent a build up of conjunction squalls, Oltrogge recommended space agencies and governments should “stop conducting direct ascent ASAT tests, and do not intentionally cause fragmentations to occur that create long-lived debris, which puts the spacecraft operator satellites at risk.”
“[They should] adopt internationally-established consensus best practices for space operations, to include minimizing post-mission orbit lifetime, [building] spacecraft that have a reliability of their post-mission disposal function of at least 95 percent, and sharing data, [to] be transparent about one’s operations, [and] help with capacity-building for new spacecraft designers, builders, and operators,” he told us. ®