Rudder Actuator Blamed
The flight of NASA's X-43A has been postponed, due to an
incident with the rudder actuator on the booster. On Feb 11, during
setup at Orbital Sciences Corporation for testing of the rudder and
its actuator, an anomaly caused the actuator to go hard over and
hit its mechanical stop, exceeding the torque to which the units
were qualified. Although the actuator may still function normally,
it will have to be replaced. A joint government/contractor incident
investigation is under way to determine the cause and corrective
actions. The stack, consisting of the X-43A and its modified
Pegasus booster, will be air-launched by NASA's B-52 carrier
aircraft at 40,000 feet altitude.