NASA’s Space Launch System (SLS) rocket completed another milestone on its way to launch with the Umbilical Release and Retract Test (URRT). The URRT was performed on the rocket on September 19 while it stood in High Bay 3 of the Vehicle Assembly Building (VAB).

During the test, the swing arms and T0 umbilicals at the base of the rocket were commanded to retract from the vehicle as they will during a standard SLS launch countdown.

The test occurred on Mobile Launcher 1 (ML-1) and allowed ground teams to verify and validate the mechanisms, timings, and function of the umbilical release and retract system that will separate and move the arms — that support data and communications pathways as well as fueling ports for the upper stage — away from the SLS rocket and against the tower at launch.