1.   Both now typically operate on hydraulic power, which in turn is produced by a pump driven by belts that run off the drive shaft.

2.   Experts concluded that the hydraulic power unit did not require replacement, a task that would have delayed the liftoff by several days, said NASA spokesman Rob Navias.

3.   Ford, Eaton and the EPA all see hydraulic launch as a modest beachhead that could help establish the practicality of hydraulic power.

4.   It converts the rudder pedal movement from the cockpit into hydraulic power to move the rudder.

5.   It transfers the pedal movement from the cockpit into hydraulic power to move the rudder.

6.   Shortly after liftoff, problems arose with one of three hydraulic power units involved in steering.

7.   The power control unit, which operates similarly to power steering in a car, converts rudder pedal movement from the cockpit into hydraulic power to move the rudder.

8.   A sensitive toggle switch in the hydraulic power system was blamed.

9.   Commander Richard Searfoss had only two functioning hydraulic power units for most of the hourlong descent.

10.   Half the size of a football field, the lab uses hydraulic power to simulate the destructive ground movement of a major quake.