Two-Minute Test Accomplishes All Objectives
NASA's Space Shuttle
Program successfully fired a four-segment reusable solid rocket
motor Thursday, November 1 at a Utah test facility. The two-minute
test provided important information for continued launches of the
shuttle and for development of the Ares I rocket, a key component
of NASA's Constellation Program that will launch the Orion crew
vehicle on missions to the moon.
The static firing of the full-scale motor was performed at 1300
MDT at ATK Launch Systems Group, a Promontory, UT-based unit of
Alliant Techsystems Inc., where the shuttle's solid rocket motors
are manufactured. Preliminary indications are that all test
objectives for shuttle and Ares I were met.
The test evaluation motor, or TEM-13, burned for approximately
123 seconds, the same time each reusable solid rocket motor burns
during a space shuttle launch. The Reusable Solid Rocket Booster
Project Office at NASA's Marshall Space Flight Center in
Huntsville, Ala., manages these tests to qualify any proposed
changes to the rocket motor and to determine whether new materials
perform as well as those now in use.
"Full-scale static testing such as this is a key element of the
'test before you fly' standard and ensures continued quality and
performance,"
said Jody Singer, deputy manager of the Shuttle Propulsion Office
at Marshall.
One test objective was to demonstrate the thrust vector control
system operation using only one of two hydraulic power units. The
vector control, part of the flight control system, directs the
thrust of the two solid rocket booster nozzles to control shuttle
attitude and trajectory during liftoff and ascent. During a shuttle
launch, both hydraulic power units run and provide backup power to
thrust vector control actuators. The test with only one hydraulic
power unit will validate the system's redundancy capability and
operating performance data.
Another test objective was to measure the external sound or
acoustics created when the motor ignites. More than 25 microphones
were located near the motor to record the data from the firing.
This information will be used to predict the motor's acoustic
effects and aid in the final design of the launch structure for
Ares I.
After final test data are analyzed, NASA will publish results
for each objective in a report available later this year.