Issue 88

Paper: Anti-satellite Weapon Tests to Disrupt Large Satellite Constellations

28 Dec: Nature Astronomy published a paper by Aaron Boley and Michael Byers, both from the University of British Columbia, which discusses the applicability of conducting a debris-generating kinetic Anti-Satellite Test to disrupt megaconstellation operations. Specifically, the authors modelled the affects of the…

28 Dec: Nature Astronomy published a paper by Aaron Boley and Michael Byers, both from the University of British Columbia, which discusses the applicability of conducting a debris-generating kinetic Anti-Satellite Test to disrupt megaconstellation operations. Specifically, the authors modelled the affects of the Russian Cosmos-1408 DA-ASAT test if it had been conducted at the primary operating altitude of SpaceX’s Starlink (550km). Read Full Article.

– Russia hit Cosmos 1408 with a ground-based missile at 480km and produced 1,500 pieces of trackable debris that threatened the International Space Station (ISS) and China’s Tiangong space station.

– Direct-ascent ASAT tests use a missile launched from the ground, sea or air to destroy a satellite or rocket body owned by the testing state, using the tremendous kinetic energy of the collision.

– The debris from the 2021 test created complications for satellites at higher altitudes, including SpaceX’s Starlink ‘megaconstellation’. According to SpaceX, over 1,700 of the 6,873 collision-avoidance maneuvers performed by its satellites in the six months from 1 December 2021 to 31 May 2022 were due to Cosmos 1408 debris.

– This outcome raises the possibility that a state may conduct a ‘test’ with the intent of disrupting the space operations of another state.

– For Starlink, SpaceX reports using a collision probability threshold of 1 in 100,000 for conducting collision-avoidance maneuvers.

– If the 2021 target satellite had been closer to the Starlink 550km shell, instead of one at an altitude of 480km…the authors estimate

Starlink maneuvers would increase from 24/day to 240/day…an order-of-magnitude more conjunctions. Projecting over 151 days, the expected number of conjunctions would be 36,000.

Instead of being designed to physically damage satellites, the creation of fragments through a carefully crafted ASAT weapon test would disrupt a megaconstellation by requiring a very much larger number of collision-avoidance maneuvers. This would lead to increased fuel use, shorter satellite lifetimes and possibly the degradation of services. A high frequency of maneuvers also brings the possibility of errors or maneuver conflicts, and with this a much greater likelihood of collisions.

Modeled anti-satellite test debris effects near the Starlink 550 km shell (Nature Astronomy article)