Five-Segment Booster "Key Element" To NASA Heavy-Lift Capability

A second fully developed Ares five-segment solid rocket motor, known as Development Motor-2 (DM-2), will be tested in the Utah desert by Aliant Techsystems (ATK) and NASA later this month. The five-segment rocket motor is an upgraded version of the Shuttle's 4-segment booster, and has also been identified as a key element of NASA's future Heavy Lift Launch vehicle.

The horizontal ground test firing is planned for August 31 at 0905 MDT in Promontory, UT. There are 53 design objectives that will be measured by over 760 instruments during the test.

DM-2 is a "cold motor" test. That means the motor will be cooled to 40 degrees F to measure solid rocket motor performance at low temperature, as well as to verify design requirements of new materials in the motor joints. These new materials will allow for the elimination of joint heaters that were necessary in the original 4-segment motor design. This will save significant weight, further reduce system complexity and simplify launch operations, while simultaneously delivering increased operating margins at lower ambient temperatures.

Other objectives include data gathering on vital motor upgrades such as the new insulation and motor case liner and the redesigned nozzle which increase the robustness of the design. When fired, the motor will produce a maximum thrust 3.6 million pounds, or 22 million horsepower.

The cases to be tested have all previously flown on the space shuttle, collectively launching on 57 missions.

FMI: www.nasa.gov