The US Air Force 18th Space Control Squadron forewarns a potential ‘conjunction’ between the European Space Agency's Aeolus satellite and Starlink44, on 2 September at 11:02 UTC. Experts in ESA’s Space Debris Office calculate the collision probability. As days pass, probability of collision increases, and by Wednesday 28 August the team reaches out to Starlink to discuss options. Starlink do not plan to take action. ESA’s threshold for conducting an avoidance manoeuvre is a collision probability of more than 1 in 10000, which is reached by Thursday evening. On Sunday the decision is made to implement the manoeuvre. On Monday 2 September, a series of thruster burns are triggered at 10:14, 10:17 and 10:18 UTC, half an orbit before the potential collision – the first ever 'collision avoidance manoeuvre' performed by ESA to protect one of its spacecraft from colliding with a satellite in a large constellation.