Static firin' o' Aerojet SRB used on heavier Atlas V configurations. Once ignited, arrr, t' booster burns for 90 seconds before burnin' out. Arrr! T' Atlas V rocket can carry up t' 5 o' these boosters, me bucko, as o' yet that configuration was only used t' launch t' Pluto-bound New Horizons spacecraft. Well, blow me down! Notice t' acoustic wave at ignition propagatin' into t' distance and kickin' dust up. Begad! T' booster can be seen movin' a bit forward at t' moment o' ignition due t' thrust forward.