NASA and Alliant Techsystems (ATK) are preparing to conduct a second full-duration test firing of the first stage of the Ares 1 rocket that U.S. President Barack Obama has proposed canceling as part of a broader overhaul of the U.S. human spaceflight program.

The five-segment solid-rocket booster, dubbed Development Motor-2 (DM-2), is scheduled to be fired Aug. 31 at ATK’s Aerospace Systems facility in Promontory, Utah. The first full-scale Ares development motor, DM-1, was successfully test fired last September.

The Ares rocket motor is derived from the four-segment solid-rocket motors that today help boost the space shuttle into orbit.

Announcing the upcoming test Aug. 5, ATK said the DM-2 will be cooled to approximately 4 degrees Celsius to measure the solid-rocket motor’s performance at low temperature. The test also is intended to verify new motor joint materials designed to eliminate the need for heaters used today on the space shuttle boosters. The change is meant to save weight, reduce system complexity and simplify launch operations, ATK said.

Other objectives for the test include gathering data on such motor upgrades as new insulation, a motor case liner and a redesigned nozzle. When fired, the motor is expected to produce a maximum thrust of 3.6 million pounds.

Although NASA’s 2011 budget proposal calls for canceling the Ares 1 crew launch vehicle and Ares 5 heavy-lifter in order to pursue a new, possibly kerosene-fueled rocket, legislation moving through Congress would require NASA to incorporate Ares technology into the nation’s next heavy-lift rocket.