Chopper using his rocket booster
Rocket thrusters, also known as rocket boosters or jets, were a pair of mechanisms that afforded R2 series astromech droids the capability to take to the skies. The well-known droid R2-D2 came equipped with such a system of boosters, which he used to his advantage all throughout the Clone Wars. Nevertheless, by the time the Galactic Civil War came about, R2-D2's boosters had been out of commission for quite some time, and his warranty had expired long ago, having sustained damage at some point following the Clone Wars. Despite this, R2-D2 managed to get them functioning once more, albeit briefly, while on Endor during the First Order-Resistance conflict. In addition, U9-C4 and QT-KT, two other droids, were also equipped with rocket boosters during the Clone Wars. During the Age of the Empire, the C1-series astromech droid named Chopper possessed a single rocket booster. The extremely dangerous assassin droid BT-1 also had rocket boosters. During The New Republic era, the R5-series astromech droid R5-D4 had rocket boosters which he used to enter and escape Gideon's underground base.
