During rocket launches into congested LEO bands, what must trajectory planners coordinate to ensure safety during initial ascent?

Their launch path against predicted locations of cataloged objects

Launching new assets, especially into the heavily trafficked Low Earth Orbit (LEO) region, requires rigorous pre-planning because the launch vehicle has a relatively fixed path during its initial boost phase compared to a free-flying satellite. Launch providers must coordinate their planned ascent trajectory with space situational awareness centers. This coordination involves checking the predicted paths of all significant cataloged satellites and debris against the rocket's flight path. If a conflict is identified during the ascent phase, the launch time or trajectory must be adjusted to ensure the vehicle avoids existing orbital hardware while traversing the most congested space areas.